Why go with LEDS? ...and that is what is supposed to be behind there anyway.
Paigeoliver is going loco. Happ, themselves make wedge based LEDs to replace those incandescent bulbs so I would hardly say that you are not inteded to put LEDs behind your coindoor. That said you just have to ask yourself, "Would I rather change bulbs once every two to six months or once every ten to twenty years?"
All my games are twenty years old, so I am always speaking from a point of view of what they did back then.
Since 20 years ago, LED technology was in its infancy stage, it only makes sense for them to use incandescant bulbs.
However, it's just a smart thing to do to use LED nowadays. Initially more expensive, you'll save money since most are rated for a life of >10 years. Power savings as well, but that's secondary. You also get the added benefit of nearly no heat given off.
To each their own, really, but I'm going to retrofit with LEDs on my coin door. The best part is I don't have to change anything, just pop a bulb in.
nb: wouldn't it be a good idea to use a high mcd red LED, as opposed to a white one? They're cheaper, and most rejects are red anyway.