Hey Matt, I'm in the same boat and about to attack my overhead for the 767-300. I have an alternative for you that I was put on to by Henry and I believe they are quite easy to wire up. I will be buying these shortly and trying them out as they are the cheapest Led pushbutton for what you and I would be after. I don't know the exact dimensions but I'm guessing close to 2x2 cm.
http://www.mycockpit.org/photopost/d...pushbutton.jpg
http://cgi.ebay.com.au/ws/eBayISAPI....=STRK:MEWAX:IT
Matt, they're easy to wire. If you are holding the switch with the led on the bottom, the pin layout is like this:
a b c
d e
f g h
d and e are the LED connections (e is the cathode) and f and h is the switch connection.
I think these will achieve a satisfactory result once wired up.
Best of luck Matt.
Drewsta