They are 5000mcd 5mm UV LEDs, as found on ebay. Operating voltage per LED is around 3v for these leds. The flashers were a bit weak when driven off 12v so I plan to use some smaller, less voltage hungry ones soon.
Flashers still flash (as they still go in the same sockets they were meant for) but the #44's stay on all the time. Had the #44's working for quite some time in Tron with no issues.