John Osborne explains that he did not design Pro-Football but did design Gridiron:

The single-player Pro Football was just going into production when I started at Gottlieb. Pro Football was the only game that ever injured me. The story:

Since the game was in early production, there was one or two set up in the showroom at Gottlieb. Sometimes after lunch we'd go play these games. What I hated about Pro Football was that the ball could go out the side rollover while the motor was still running because of other scoring. The outlane rollover was very important --- it completed the football "run" across the playfield and gave a touchdown score. I am not much of a game pusher or tilter, but I got so frustrated from losing the outlane rollover score that I actually kicked the game. Being an amateur at this, all I did was cause an enormous bruise on my shin. At the same time I vowed that I would never design a feature like that, such a cheat for the player.

Of all games for Wayne [Neyens] to ask me to remake! This was my chance to fix this unjust feature. I made no change in the playfield but rather added a delay relay so that the rollover was "remembered" until the motor finished. I didn't tell Wayne I was doing it because I was afraid he might veto it on the grounds of adding expense. When he saw the result he was glad I had done it.

Reportedly, this game was made as a kit as well as a complete game. We asked Ken Fedesna, Executive VP/General Manager over Williams/Bally/Midway from 1988 until their close of pinball production in 1999, who provided this detailed information:

It was referred to as GridIron II in all my notes to differentiate it from the original GridIron, so your assumption regarding this is correct. The first mention in my notes about this game was on 6/1/84 where we were trying to come up with a preliminary cost estimate for building it. A prototype build was released, but nowhere in my notes do I have the number of proto units to be built or what was built. On 10/5/84, my notes indicate that the proto cabinets and playfields were due in the following week. My notes also indicate that it was to use System 8, and that we were building 4 ramp assemblies with the motors we had in stock and had to get more motors to build more. On 10/12/84, my notes mention for the first time that we were considering making this into a conversion kit for Pennant Fever in addition to a dedicated version. On 10/29/84 (after the AMOA Show) we released 150 dedicated units and 10 Conversion kits for Purchasing to buy the parts based upon getting initial orders at the show for 150 dedicated games. Production was scheduled to start 12/17/84 at 5 to 10 per day. On 11/26 my notes indicate that production was still scheduled to start on 12/17/84. Then on 12/20/84, the entire production of this game was canceled and all parts on order were to be held until Spring to build more baseball games. At that time, our cabinet supplier had built 45 cabinets, and 60 backboxes and was told to stop. Same for Ad Poster with regards to screening playfields. If I remember correctly (?), the reason we canceled building this game was due to how late in the football season this game would be being introduced. At 5 or so a day, the 150 units wouldn't be completed until February 1985 when the football season was over. So, the reason there is no record of building any production units of this game (dedicated or kits) is because we never did build production units.

It's pretty clear that in 1982, while they were trying (and failing) to sell many Iron Maidens or Orbitor 1s, Stern was working on their next game, LazerLord. They were building up a whitewood in a leftover Viper cabinet (a completely normal series of events), and had already gotten sample backglasses produced.

In the November 1982 Replay Magazine, on page 37, is an article headlined "Stern Shuttles To The Suburbs" detailing how they were selling their Diversey Pkwy building, and had consolidated all operations in their URL subsidiary's building in Elk Grove. It includes a line that starts "Stern has ceased all pinball manufacturing..." I believe that's just when they made it official, by not setting up a pinball production line in Elk Grove, but the decision had been made months earlier... thus the last date of June on the whitewood's ROM labels.

I don't have at hand my late-1984 Replay Magazines, but in early 1984 they were clearly on the downswing, with their VP resigning in April, and a May story detailing the sale of the Seeburg assets in March. In the March 1985 issue on page 18 is an article titled "Stern Liquidates, But Gary Stern Opens Carrin Electronics".

Stern absolutely showed a game called "LazerLord" at a trade show. That was the reason for the existence of the flyer (shown in this listing). The flyer uses the tagline "Pinball Is Back!!!" and has their Elk Grove Village address, along with a crappy photo that clearly matches the complete-with-artwork narrow body version of the game. While I don't have the issue of Replay with a report on the fall 1984 trade show to prove it, I think it's pretty obvious from the clues that's when it was.

So the theory that, in a desperate move as the company was faltering, Stern tried to release a pinball using existing parts (their stash of LazerLord glasses, and the already-engineered Quicksilver design), would seem to be correct.

So this explains the two dates, 1982 and 1984, and the two different games with the same name.

1982 is when they were developing the [whitewood] game, and probably would have released it later that year if they hadn't exited the pinball business.

1984 is when they tried to sell a [narrow body] game by re-using existing parts, but a game that required no engineering, because they had no pinball designers on staff by that point.

They are two totally different games. The 1982 whitewood was the original LazerLord idea by Joe Joos, the 1984 game is just a reused game design, with the LazerLord art package applied to it.

Anyone who has ready access to late-1984 Replay or PlayMeter Magazines, who can nail down that last little bit of proof on this? I'll eventually find it if nobody else does, but my copies of those magazines are in storage elsewhere at the moment.