Based upon what I've read in these threads, I have a feeling that the NUSA piston is heavy as a brick. You may be better off replacing it anyhow. Just my 2 cents.
I believe it's the same piston as I had, same markings and size. Pretty certain mine came from CMW, it looks the same as whats in their catalogs for the big bore kit. Barely can make out "NUSA" and "cyl=87.00" stamped on the top. Weight is approx 417 and 499 w/pin. Still no idea where it is actually made though.
Was yours in your bike when you got it? Do you have any estimate about when it was installed, and if rings can be ordered?If CMW had them, they were likely RE overstock from Lightning production.
Is that CMW this, you are talking about?http://www.cmwmotorcycles.com/index.phpTheir page says only this: Sorry, our website is not available. Please contact us by phone for assistance.