Good question !
I suspect it was a Clearhooters
Pretty sure you are right.
It looks like a Clearhooters ?
And, not surprisingly, there is nothing listed in the Lucas
The brochure (throughout) only refers to 'electric horn'.
Doesn't go into any detail, and doesn't give a better view.
I've got a project one of these - note the J2 model has tubular girders - so I guess I need to find out ?
Or just use a supercheap $5 one, and ignore the pundits ....
It didn't come with anything in that dept ...