I just offered to clean up a neighbor's rusty and grime-encrusted carbine that he "...paid $90 for 40 years ago." SN is in the 100,000 range so I assumed it's an Inland. The top front of the receiver is stamped "Universal Hialeah FL". I searched "Universal" in this forum and found out that rec'r production was contracted out by Inland. Fine so far, but when I removed the stock, I found that it has two (2) side-by-side oprod springs (similar to an AR180)! My experience is with M1 rifles and I only have one carbine (single spring) so what is this rust-coated thing? Thanks.

Chaz