Maybe it's just me, but a couple of the bells used on ABC Password certainly sound like they were re-purposed for FF. The bell used after "The password is..." (and to reveal the Lightning Round words in 1974-75) sounds like the one used for Fast Money, and the higher-pitched bell used after a correct guess in the Lightning Round (and after a correct preliminary round guess in 1974-75) seems to be the same as the one used on FF when tallying the $5/point total.
The "#1 answer"/"banking money"/"finished Fast Money before time's up" chimes from Family Feud were also used when someone won One-on-One in TTTT90, no?
I think the face-off buzzer was used to indicate a wrong answer on some Goodson show...can't quite remember...
The SFX used on syndie TJW's Beat the Devil round got around quite a bit too...
Yep, Penny Ante, and Double Dare '76 (on DD, it was available at two different pitches....listen carefully...)
As per Buzzr's Lost & Found, I think it was TKO that used Hot Potato's correct answer chimes (as opposed to the brief time when HP used the Sale of the Century "ding" for correct answers)
/SOTC borrowed the Winner's Circle countdown for the Speed Round.
//Then they switched to a "Jimmy Hart Version."