Would it work if you took a square of 1/4" aluminum flat stock, drilled a large enough hole, and threaded the hole to match the lock threads?
Well, the flat stock and the hole are not a problem. Finding a tap that matches the threads of the lock body is going to be the problem. By the time you engage a machinist to custom cut threads you are back up around the price of a whole lock assembly.
I am sure that there are quite a number of these lock assemblies in motorcycle junk yards that will never be used. I just don't know where to find one.
Mort