decoding 1981 GMC options

[olblue81]

I tried searching and came up with results of 67-72s only. I bought a 1981 GMC 4x4 and I want to decode the options on it. I have the glove box sticker but it only shows the codes, no descriptions. Where can I find a resource that lists the codes? Previous owner said that the truck was ordered with buckets but I'm skeptical because the seat belt retractors look like they came from the middle row of a burb.
The truck is nothing special- tilt and cruise, no a/c or pulse wipers, no tach. Only thing really interesting is the buckets. PO did claim it had posi. Has Sierra Classic fender badges but no trim on the back of the cab. It is pretty crusty, but from what I can see the cab floor is decent, only needs 1 door sill and the usual rockers and corners. PO threw in front clip, front bumper, corners and rockers.

Immediate plans for the truck include new body and paint. After that will be engine, trans and gears. Possibly a 2" lift and 33s. Most of the parts going on it will be leftovers from my 2wd. It won't be anything special, just a farm truck with a fuel tank, air compressor, tool box and welder in the back.

Bringing it home
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Options Sticker from glove box
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my 2wd, Ol Blue
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