Interesting.

According to Steve Ritchie (on IPDB) 10 prototypes were built, but there seems to be a number of games with prototype features making it confusing.

I have a prototype (with an "X" in the serial number) and it has different cabinet art than the production game. Your serial number seems to show a later game, but I have many of the differences you have on my game (clear beacons, "proto" stamped on the rom's, different sounds, instruction card).

Does your cabinet have the normal production art or the art that's missing the red stripes (and entirely different art on the sides of the head)? Also, what does it say on your speaker panel? Mine says "Williams Number 1 in the World". I believe the production games say "Williams Pinball #1 in the World".

F14 was super popular (#6 selling Williams game), so over the course of production, Williams used any parts of any color to keep the line moving.

Sneaky ebay sellers have even been known to replace lamp covers to all clear, and then claim the game is a prototype - even though the playfield has the much latter lamp boards.

The 10 prototypes have a X in the serial number, and the blue insert at the top says "Blue Plate Special" instead of the production playfield "Hot Streak" (above Yagov's head).

Supposedly the first 200 games off the line had PROTO ROMs

image-A28_(resized).jpg

What are the playfield insert colors?
Inspect and check the beacon assembly.
Prototypes are different.
Early production sample games were also different.
Production games standardized the blue and red colors for the arrows.

I have an early sample.

That covers a lot of early production units, not prototypes. The biggest thing you need to look for is an X in the serial number, that would identify a prototype. While it is possible that you could have a prototype with production cabinet art, usually the prototypes have the stark black cab without the stripe. Now THIS is how the protos would look. What is the serial number you have?

image-17_(resized).jpg

Yeah, I got all excited that I thought I had a proto too when I first got my Tommycat.

I had a diamond plated riverboat gambler that was the same way. Showed all the features, got me super excited, then turned out was just early production.

Hey that looks kinda nice!

This is actually the earliest F-14 Tomcat prototype.

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It is always fun to come across these early production games.
Just last year I picked up a Firepower that had a routed cut out behind the stand up targets and even had a factory switch installed in the cutout that scores points. But no drop targets so the switches can only be hit by hand as the ball will never touch them.