Pedro,
Hola, and welcome to the forum. We look forward to more photos of your interesting modified bike. As to your thanks for the welcomes, de nada.
Scarcity of BSA's is not unique to Mexico, even if it is a bit leaner there. In the twenty years I've lived outside of Chicago I haven't seen another A10 on the road and very few A65's. If I ride sixty miles to the nearest vintage motorcycle shop, or maybe go to a British vehicle show, I'll see them. Otherwise, mine is pretty much alone near me.
Richard L.