thanks for the info on the Nikko YP horns - will see what i can find
Nothing wrong with the NIKKO horns they make noise.
For what its worth if you are going to use the stock bracket (83-1254) I would suggest the addition of a small brace from the base to the bent parts. I have repeatedly seen the bracket break at the bends. I would also suggest safety wiring the horn bodies to the bike. As when the bracket or horn bracket breaks (note I didn't say if) you will not have a scratched fender or lost horn. Been there done that.
Regarding the 1970 T120 horns. Early models (up to about January 1970 builds used the Dome Style horn Stuart mentions (part numbers 60-2256 & 60-2257 . The 2256 was a Clear Hooter P201 and the 2257 was a Clear Hooter P101) About December 1969/January 1970 there was a problem with the previously mentioned horns.
Was it a horn availability or horn quality problem I do not know. I suspect it may have been the bracket breaking due to the horn weight.
Regardless about January 1970 Triumph starting using Clear Hooter horns Triumph part numbers 60-2623 & 60-2624 (Clear Hooter part numbers HF80 lo note & HF80 high note) These are the same horns used on 1971 and later T150's These horn resemble the LUCAS 6H and is where the confusion comes from.
1970 was a long production year with many running production line changes that were not necessarily documented properly.
K