Toujours avec l'aide de bigincher, je peux souder les pattes de fixation du klaxon.
Je me demande toujours comment j'aurai pu sans son aide souder ces petites pièces.
voici son travail:

Always with the help of bigincher, I can weld horn mounting brackets.
I still wonder how I could have without his help weld these small rooms.
Here his work:

Siempre con la ayuda de Bigincher, he podido soldar las patas de fijación del cláxon. A veces me pregunto cómo habría podido soldar estas piezas sin su ayuda.

Aquí está su trabajo :

In the first photo, I used a straightedge and clamped it across the horn blocks, aligning the top with the center of the top holes. I used whatever I had handy, in this case a piece of 1/2" x 1/2" square stock.....

Then I used a common tape measure to measure vertically from the casting (for intermediate frame tube) to the top of the straightedge. Dimension is 6-5/16".....

A couple of notes:
You should fabricate a template to hold the horn blocks at the correct distance apart. I used a piece of 1/8" x 2" x 8" flat stock (not shown) drilled to accept the horn blocks at the proper distance apart. (You should use your horn to measure actual distance between threaded holes in horn blocks. If you do not have a horn, I can provide you with dimensions of my horn.)
Use a level on the motor mount to level the frame, then use a level on the template.
A slight amount of variation up-and-down is acceptable. Probably + or - 1/16".
Factory weld is on top and bottom of each horn block, not on the sides. The crappier the weld, the more authentic it will look. (not kidding...!)