Kevin, I use to work for a BMC dealer and acquired this original BMC parts catalog that covers cars through 1967. Since I’ve own a Bugeye for 43 years I have reference it many times when I wasn’t sure.. It shows every component on the car down to screws and washers, however regarding your situation of the make up to windings of coils, magnets, diaphragms, and such it does not. But if you have any other questions I do not mind providing that information to you...
I myself use to be a purest, but found myself bored; I guess 43hp just wouldn’t cut it for me any more. I quickly got tired of barely having any brakes when you heated them up and the car wouldn’t stop.. Or when you hit the gas it wouldn't throw you back in the seat. However I wanted to keep as much of the car British looking but with many British enhancements in the performance direction a (British Street Rod). Such as 4 link coil-over’s, front and rear disc, 5 speed, very trick 1380 BMC engine and many more up dated enhancements.
I’m glad that this information was helpful, my hopes are that you’re able to make your horn function which ever one you choose