A riding buddy of mine gave me a Cyclone RD just like you describe, cmdr, it has no paint on the plate and it obviously never had any paint. Judging by the many pics of Cyclone RD's I've seen on this forum, this is apparently very unusual. But at least now we know our derailleurs aren't unique.
Btw, according to the component date codes on the vintage trek site, mine was made in 1974. Do you know the year of yours?