[Garcia]

Update on progress:
First of all, thanks to everyone who has made suggestions and pointed the way.
The fuse I have is a five dollar inline glass 30 amp fuse (not a circuit breaker) from the hardware store installed between the x and the y. Installing it was the first thing I did to the car. I took nkaminar’s suggestion and disconnected the wire leading from the generator to the light switch and haven’t had any more blown fuses. I have a new lighting harness on order.
When I got the car, there was a button for the horn attached to the steering column with cable ties. The seller told me he didn’t know why the horn button didn’t work, but that he had rigged that up as a solution. The more I find out about this car, the more I realize all the red flags I should have noticed when I first looked at it. This is indeed a learning experience, and maybe I’ll be a lot better prepared if I happen to buy another Model A.