Thanks again to everyone for the parts education.
I was able to improve my Google search and find out a lot more with the direction from your comments.
It is a Palmetto Armory bar stock machined lower, with SGW stamped in it a few places along with OLY WA.
SN is 1xxx so it think it was made in 1979.
The 5.56 / SS barrel stamp matches up to 2 barrel pictures for Olympic Arms 20” HBAR barrels. One is in an archive here.
The Stock matches a few old Olympic carbine ad pictures that I found. Buffer tube has a 2 hole ring instead of castle nut.
Buffer is real heavy and rattles. Has an aluminum bumper instead of a rubber one.
Haven’t been able to get the handguards off to check under them.
Here is a better picture of the grip.
Attached FileMight have found a complete carbine upper for this build in Columbus. Supposed to pick it up tonight.