Think they used to be available from Deckel....Upgrades in the field from Dialog2 to Dialog4 got the stick on characters..
Had several controls so fitted.....Not elegant. Made the keys taller and in time the stick on characters often pealed or the printed character was worn off.
Perhaps Singer might have some old stock, don't think DMG is even an option.
Native Dialog 4 keypads have the characters molded into the face of the key...and they don't wear out...Just feel better to the touch, but $$$$$$ to replace.
Bought some good used native Dialog4 keypads (2) off e-bay about a year back...nice shape, but still costly, seller knew what he had, think i paid $400.00 for the pair.
Interested if someone out there still has the transfers......
Thought about engraving the original Dialog 2 keys, but they can't be removed (at least i haven't figured out how) without killing the button top...Sort of a one time snap together part.
Let us know what you finally find...
Cheers Ross