The location of the wrist pin is the critical part, it sets the height of the piston in the bore. You could shim the cylinder if the ports are close, maybe do a little port matching with a dremel. Then, bore the cylinder to match the piston diameter, and have it replated. Sounds like $$$$$$. One other thing, the diameter of the wrist pin; does it match the small end of the rod? Why bother? If you gotta have a better piston, there are many sources for a custom-made piston, which I think would be much cheaper than adapting that 49mm piston, which will give you VERY little if no performance gain. Plus, a larger piston with pin will add weight, not good for crank balance. But that's just my opinion.