So I was at a fun show today, and ran across a Rock-Ola M1 Carbine that they were asking $795 for.

Considering that every other carbine at the show was listed for $900 or higher, one would think that this thing would have flown out the door. But....

There was something....... wrong about it. I can't place my finger on it, and Lord knows I'm no expert, but let me share what I saw so you can tell me if I should go back to this guy (he's local) and snag it.

1) The rifle did not have the bayonet mount. The whole part just wasn't there.

2) The bolt was shiny, as in "almost like stainless steel". Now, I recognize that parts can and are replaced, but it just seemed so out of place...

3) The finish on the gun seemed painted on. I recognize that in some cases (Jungle Carbines and cheap AR's) this is easy to spot, but on this one it wasn't. It only SEEMED painted. The finish (especially under and aft the rear sight) was just a little too shiny. The rest of the weapon seemed in great shape. Perhaps too good? Sadly, I didn't look inside the barrel.

Again, I know just enough about this stuff to be dangerous, and I'm in no mood to be taken. What do you guys think? Was it worth it, or was I wise to avoid it?

I should point out that the dealer is well-known to my FIL as an honorable guy, which is why I'm torn on all this.

Many M1 carbines were issued with w/o the barrel band that facilitated the bayo mount. I've got a number of Bavarian carbines, NONE of them have that type of barrel band. I don't think the bayo mount should be a distractor unless you've got a collection of bayonets you want to mount.
As far as metal finish goes, any part if not the entire carbine can be reparked, and there are plenty of quality smiths out there than are capable of a great repark for not too much $.
Rockolas are scarce, right up there with IBM's. I'm suprised it wasn't scarfed up as well. The two things I'd be most concerned with would be muzzle wear, which can be checked with an M1 garand muzzle gauge, or if you have to, use the bullet end of of a 30:06 cartridge inserted into the muzzle and the bore itself.
I'd also check to see who manufactured the bbl as well as checking for import marks.
I guess it all boils down to what you want to do with it. Shoot it or safe queen it. If it's got the original bbl and it's not an import, the value goes up. If it's an import but the muzzle/barrel wear is nice, the price is still reasonable especially since the CMP has no more. My best shooter is a Winchester import that gauges 2+.

Sounds like bolt was very worn with no park, makes you wonder about the rest of the rifle.
Maybe it was still there because the bore/muzzle is toast

M1 Carbines where not manufactured with the bayo lug on the barrel.  They came with what are referred to as "flipper" rear sights (two apperatures on an angled blade that flipped from one to the other and no bayo lug.  

After WW2 when they where reconditioned the lug was added and the adjustable rear sight was added as well.  Some carbines produced late in the war did have the adjustable rear sight, however.