Morning Michael Hampton
I suspect at some point in the past the standard steering wheel had been replaced with something like a Nardi or similar wheel and the metal rod in the column that gives the horn push its connection removed. Upon refitting the standard steering wheel this rod was not reinstalled. Hence no horn!
As it happens I’ll be working on my own car today/tomorrow replacing my steering wheel so I’ll add a photo of the rod etc I’m referring to. I don’t have a spare unfortunately but maybe Laurence does from the Cabby he is breaking.
Regarding your Targa panels, I might be able to help you there also. I’ll get back to you on that. I know someone who is breaking a car. I’ll have a word