In the early '70's OREGON made 3 different .063 1/2" chains.
10AC Chipper, 10AL Chisel and 32 Micro-Bit. By 1987 they were only making 10AC chipper which is what I have as well as some CARLTON and LASER...all Chipper Style. Even back then it was not an inexpensive chain (50+ cents a drive link).