All Hei Hei have made in usa on bb shell.
The drop outs are exactly the same as mine and mines a pre-bullit drop out model. 1990/1991.
And to top it off, my best mate has a 19" Hei Hei of the same era:
- Same drop outs
- top tube cable stop and also the "ring" cable stop on stays
- Made in USA on BB
- same extended headtube 1 1/8th headtube
Ill get some pics..