Corsaro1) Bicycles was created by Rick Wilson in 1983, in Tiburon, CA, just 8 miles from Mount Tamalpais, the home of mountain biking 2) Earlier, in the 1960's, Rick started Wil-Go as an importer of French Gitane road bikes. He later helped found Western States Imports with Michel Weiner, which then created the brands Centurion and Diamond Back. Corsaro remained separate from WSI and apparently produced bmx, mountain and road bikes from 1983 → 1987 3)
“America” is only where they were sold. As WSI said, “Boxes in, boxes out. Everything else is marketing.”
ebay
SunTour Mountech 5500 is 1983 correct.
1983 Sherpa
seattlebikes
SunTour XC 6300 rear (1984-85), CB-6000 brakes (1985 only, thus, full drillium with original plastic pulley rollers.)
A 1984 date is possible. See CB-6000 article here: https://www.oldschoolracing.ch/archiv/suntour/
1985 Sherpa,
facebook
Nice chrome finish. The auction listing says 1983 but the components say 1985→1986. As the paint scheme differs so much from the 1985, above, 1986 is a better guess.
1986 Mountaineer,
hibid.com
This example suggests that Corsaro persisted longer than records suggest, at least in Japan. The SunTour XC Sport 7000 rear derailleur was made from 1987→1988.
1987 Mountaineer
yahoo.co.jp
[1]. ?