@Dfb It is not extremely old since Torelli Imports was established in the early '80s. Probably late 80s (shifters/brake levers would not be original) to 90s depending on the frames they were using. It is a cyclo cross design (might be gravel) so I am surprised to see fairly narrow tires on it if original. Torelli did not make frames they merely badged them with their name. Their frames were made by various Italian shops (Mondonico for one; Torelli also distributed Modonico bikes) at the start (and later US and Japan made bikes); not sure if all their newer frames are Italian.
If you contact Torelli with the serial number I would hope they could help you out.
Basic guess on value is about $200 to $300; if top end tubing and components $300 to $500 depending on the bike's specific details. That is very general guesstimate without more info; and market value is based on region where it is being sold and also frame size which can limit your market if it is a particularly small or large frame (yours looks about 57 to 58cm seat tube c-c). It is not a collector's bike and that is why value is not that high (given its apparent condition), nor is Torelli considered a true bike company that makes their own frames. I am not knocking the brand since they are one of many brands selling quality frames built by others under contract; nothing new in the bike industry. I am not a fan of using a somewhat misleading name implying an Italian brand; but unfortunately that has also been done in the bike industry for decades in countries from Japan to the UK and many more.
If you want a better idea as to value and year then take the bike down and take a bunch of detailed photos of the frame details (lugs, tube conjunctions, drop-outs, decals, markings) and components. Since you believe it to be original we may be able to determine a value and year based on parts' models and date stamps.
Is the seat tube stamped with a size/diameter (e.g. 27.0, 27.2). Value will depend on (aside from condition and function) quality of workmanship, grade of frame tubing used, and level of components.
The high stack of the headset and position of the stem insertion are somewhat bothersome. For one it looks wrong, and the stem might not be properly engaged in the steerer tube. With the headset spacing that high it makes me think the fork was replaced with one having a longer steerer tube either due to custom needs ( wanting higher stem/bar position) or fork was damaged and someone got a fork too big and did not cut it to size. Regardless, I would pull out that stem and make sure it is inserted enough into the steerer. Actually, I would pull the fork off and have it cut down like it should be. That bike did not come from the factory with that headset set-up unless it was custom ordered that way.
That bike would make a great commuter/hybrid/gravel bike with different tires; right now it is more of a road bike set-up for speed.