What year?
I think from the picture you may be looking for a later one than Dan sells.
Not sure but I think his are for the 60s cars.
I also think that small extra plug on the pictured one is for a key switch which none of my 70s cars has.
Just don't use the plug.
All of the later ones I've found has a cheaper copper piston INSTEAD of the better original style roller horn button pick up.
If anyone knows if a better one is being reproduced for later cars PLEASE post.