I have done the bolt trick on a couple of bikes using the wrong type of wheels. Works fine, but it might be tricky with that garelli tube swing arm.
I would be concerned about getting a hole straight through, and the diameter bolt you need to use for it to be strong enough to hold while braking hard, is not going to leave alot of meat left on the swingarm. I would then have to be concerned about structural safety of the swing arm at that point.
I would end up having to take it to someone who can weld and have a tab put on. I hope you can get it to work for you.