Bigyeti:
Since he's a friend and has owned the Uni for 30 years, how does it shoot? If it shoots fine and the cam area of the operating rod handle is solid - meaning you cannot see the lug on the bolt that engages the op rod through a parallogram-shaped hole in the op rod, then the rifle might be OK for $200 to $250.
If the bolt lug is visible through a see-through cam section of the op rod, or if the weapon jams now and again, I'd let it pass.
The earliest Unis had a number of GI parts and usually a die-cast trigger group. I have a low S/N wood-stocked Uni that I replaced the die-cast trigger guard/housing with a GI unit, and had to fit the front lug a bit is all. I still have it, having sold an Inland, a Rock Ola, and a Saginaw because they would occasionally jam on ball ammo (esp. the as-issued Rock Ola with early safety, upper HG, and flip sight) and this Uni would not. The GI carbines went on the block to fund the first of a few FALs.
The early Unis were actually fairly reliable shooters, then Universal got inconsistent and also started de-contenting the weapons. A few friends also bought early Unis and with the exception on one that is deceased, the others still have theirs, or passed them to sons ro grandkids. I used to mess with M1 Carbines a lot in the 70s and in my experience, the Unis and Plainfields with the open op rod cam slot were trash. 30 years would potentially place your friend's weapon in the right time frame. If he is trying to sell it outright and not to you, I would add about $50 to the $200 - $250 I mentioned above. You will not get half that in trade from a dealer, so I recommend walking it around a show. A Uni para is fairly priced at $250 to $300 should be gone inside 90 mins at a decent sized show.
Noah