[Mr70]

Those are kickass cars!
I've encountered that OW tag on a few other 71 GS's.
A very stout trans. that was build better then the std.
TH400 and assembled in the same vein as the CW/CY 1970 Trans.
That 233 stamping is the day the starting assembling it,i.e August 21,1971.
1516 is the serial number of the trans. itself.