The lamps you speak of are called "Flashers" - they are #455 Lamps available from either Sponsor. You just place them behind the word "FLASH"
Flipper rebuild kits ?
Buy a flipper rebuild kit - but - you will need parts to rebuild the upper flipper. What I did was buy a williams coil stop and plunger/link. There was also a requirement for an "advanced" EOS that was used to power the upper flipper.
The part number for the "advanced EOS" is "SW-2010-A ". You use this in the place of the normal EOS on the bottom RHS flipper. Move the "normal" EOS to the top RHS flipper.
Coil Stop - Use either part number A-7414 (original part number), or A-8143 - which is the equivalent.
Plunger and Link - Use either part number 02-3407 or C8230
Lucky I kept my notes from my FLASH resto