Looks like a Eagle Carbine 45
Here's a 2008 ad for one, hope it helps.
Eagle Open bolt .45 Carbine (built like a grease gun, looks like a thompson) $1800
We've got a little something special for you guys today.... one of our out of state guys snapped up this little gem before anyone else figured out what it was.
She's an open bolt semi automatic .45 cal carbine called an "Eagle"
Back in the 1960's this was a poor man's plinker, and was manufactured alongside another (nearly identical) carbine called the "Spitfire" which you all might have heard about.... what with the BATFE reclassifying them all as machine guns and forcing them to be registered.... You see they had this little problem where in between the safe position of the safety and the fire position... there was this place where you could stick the selector and it would run full auto.... (the eagle variant used the dissconnector as the ejector so it didn't have the same issue with the fire control geometry)
Well, the Eagle managed to slip under the radar somehow and is still considered to be a Title 1 firearm.... Its a crude, simple, and absolutely fantastic.
This is as close as you can get to an open bolt greasegun in the state of CA... some owners have actually dropped standard greasegun bolts into these guns to aide in extraction under sustained rapid fire.
These use regular grease gun magazines and are..... well... for lack of a better word just freaking awesome.
We were able to get an amazingly low price on this thanks to our out of state purchaser jumping on it immediately... and instead of charging what its actually worth, we're going to pass the savings along to you guys....
So this bad girl can be yours for the dirt cheap price of $1800 +tax If you pay via cash/check/or money order we will ship to your local FFL for free, or we will give you free dros here in our store in Fresno.
She's currently being modified for CA compliance (she needs a mag lock and a 10 round mag) but will be en route to our store shortly.
We may never get another chance to bring you one of these at this price in this condition.
Someone is going to be VERY happy with this little girl.