Yeah, Miyata did the triple butted tubing, but not any quad butted stuff that I know of. Miyata built a lot of frames that were sold under the Univega brand, but I'm not aware of Fuji building any frames for other companies.

But Fuji have been in the high end bike game a long time, saw this 1970's beauty for sale locally a while back. The workmanship on it is as nice as many of the top quality European frames of the era: