Neither of the two transformers in coppinpr's machine are original, nor is the one in pennymachine's picture. The original is a substantial chunk with a core 85mm square and 33mm thick and two windings, one 12V for the lights and one 30V that is rectified for the relays and clickers. The cam timer and the payout solenoid run directly off the 240V mains input and don't depend on the transformer at all. It seems 12V/30V transformers are unobtainable but it's perfectly reasonable to use two smaller ones, and everything will probably still work from 24V if a 30V unit is hard to find (28V is a standard voltage, though). Coppinpr, you should probably toss out that big gray one, as it looks like a tranny out of a piece of old valve equipment and probably has 500V or so floating around on some unconnected windings with murder in its heart. Actually don't toss it, sell it, as those are rare and sought-after these days. You are also missing the payout solenoid and slide, as has already been mentioned, though at least you have the tube. The rest of it looks complete.
The picture is a bit washed out by the flash, but my machine is entirely original, old penny. This is how they looked when they were new. I don't want to brag, but I only paid 120 US Dollars for it and about another $40 renewing the rubbers and lamps. I have to run mine off an auto-transformer, since my mains is only 110V. Replacing the transformer is not an option as I still have to drive the timer and payout solenoid, and the latter is a meaty sucker that needs a family-size transformer to deliver enough current.
<edit> not entirely original. The white wire snaking down the right side from some top lights to the transformer is my addition, to keep the playfield lights on while the bingo panel lights go off at the end of the game. If you wire it so the bingo panel stays lit, the plastic framing melts.