We found this circuit in a 1968 General Electric publication. The circuit uses an SCR of the time, but any modern equivalent can be used. The relay must have contacts that support the horn current.
One of the two D-type Flip-Flops found in a 4013 can be used as a nonretriggerable monostable as...
EDN magazine in a 90's issue published this TTL technology debouncer flip flop circuit, in this...
The operational amplifier is old. The circuit is from an 80's documentation but can be designed...