So the next time I go there, what exactly should I look for that would tell me if it's collectable enough to justify that price tag?
Here is a quick primer on what to look for:
The barrel date should be no more that three months earlier than the production date of the receiver. This the date that is located just behind the front sight. If it is marked H-S, SA or has a 44 date, it is the wrong barrel and I would walk away unless the price was substantially reduced.
The stock should be a straight grip type like this.
It should have cartouches on the left side of the stock at the wrist. This is a shot of the cartouches on a Smith-Corona.
All Remington and Smith-Corona stocks will have the same cartouches, except that later production Remington will sometimes have a 'RA' stamp in front of the crossed cannons and boxed 'FJA'. Sometimes the rifles went through an arsenal inspection and will have the inspecting facilities stamp on it also. Note the 'RIA' in front of the cut off recess and the 'RA' in front of the cartouches on this Remington. It is a bit hard to see on this one as some jackass sanded the stock in the past.
There are inspectors stamps in front of the triggerguard. Remington:
S-C stamps look the same but use a different set of numbers inside of the circles/squares/triangles.
Note that the portion of the triggerguard just to the rear of the front guard screw is curved on the S-C and straight on the Remington.
There are two main differences between the original stock manufactures that are easy to spot. One is the cut out for the lower band retaining spring. the Remington cut in the stock has square ends and the S-C has round ends.
Remington.
Smith-Corona.
The other sure fire way to tell is the firing proof stamp behind the triggerguard. Remington used a 7/16" stamp and S-C used a 1/2' stamp. If the rifle was rebuilt there will be a second 'P' stamp also. Sometimes the second proof is in a square or it may be just by itself.
Remington.
S-C.
All small parts on a Remington will be marked with an 'R'. If a part has a 'RA' or 'R-P' it is a replacement. The same parts that are marked on a Remington are usually unmarked on a S-C. Most small parts on a Remington are blued (bayonet lug, stacking swivel and band, lower band and sling swivel, bolt assembly, triggerguard and screws.
There is some other small details, but this should get you started.