We actually have the clean and don't clean discussion all the time. Since we pretty well have it beaten to death, it takes a different form from time to time. Like this one apparently the OP is asking if he should even clean it one time, or the first time. There seems to be the other opinion that you should never bother, and that more guns are ruined by cleaning or excess cleaning than by neglect. And I'm a generous enough person to concede that maybe somewhere, someplace, a gun may have been damaged by over energetic cleaning attempts.
But these discussions seem to have made progress. Everyone now is pretty well accepting that you don't have an unfired gun. Almost every gun is test fired at the factory. If they practiced quality control, they'd even require all the gun to be cleaned before shipment. We also have eyes and can pretty much assume that only some of the guns are really cleaned after firing.
I have my opinions. One is that a fired gun probably should be cleaned before being put away for storage. Doesn't matter if the storage is a week or the 40 years we're talking about. If you have a gun you've just acquired, it probably needs to be cleaned. If only some powder solvent on a brush and a quick run through the bore and the cylinders showing use. Then a drying patch or two and a follow up with some oil on a patch. Good practice normally requires the exterior to be wiped with the solvent and then with some kind of oil.
The most lazy among us will scream bloody murder we're trying to force them through basic training again. They even take more time screaming than a quick cleaning would take.
I'm backing away from my old advice to detail strip every gun when you get it and clean it so thoroughly you get every trace of old junk out. Of course you can if you want, and I doubt it it has ever done much harm. At least if you know how to remove things without buggering screwheads and what not.
So my answer to the OP is yes. Clean the gun. If its only had factory firing, it won't be dirty. Chances are the powder burns won't come off and there will be no lead to complain about. But it'll shut the worst of us up about you being too lazy to clean the gun once every 40 years. If its a stainless gun, as stated, none of today's cleaning solvents or oils will do much damage to the metal. I'd actually be shocked at the solvents damaging the finish. Stainless was used so it didn't act like the wax finish on the prewar guns.
