This seems to be a recurring theme in this thread. I buy guns to shoot. I may like them for other reasons also but if I can’t shoot it than it serves no purpose. Also if I want an investment I will stick with my stocks (especially ones with good dividends) and bonds not tools. Just my 2 cents.
Don't look now, but the stock market dropped almost 400 points today...
Anyway, back to the subject, simply shooting older Colt’s won’t hurt them. From the turn of the 20th century to the middle 1960's they were a mainstay in police departments and our military services. Obviously with that record they weren't... ah... well delicate. I have an older Detective Special (1957) which is lacking about 25% of it's finish, but is tight as a drum; and accurate enough to keep its shots in the scoring rings on a B-27 silhouette target at a measured 100 yards. I will stack that up against any similar revolver of any other make. They have problems today because of owner abuse or neglect combined with a shortage of parts and qualified gunsmiths to fix them. That said a good one is still very, very good.
Eyeballing to determine chamber/bore concentricity is about as accurate as doing the same to check cylinder/barrel gap. No gun maker I know of depended on eyeballs. Feeler gauges and range rods were the rule, and still are. Unless you line-bore the chambers (as Freedom Arms does) it is almost impossible to get 6 chambers in perfect alignment with the bore when the cylinder is rigidity locked. Smith & Wesson and Ruger never seriously tried.
You occasionally find a Colt Official Police Mk III offered for $200 or sometimes less. They will handle unlimited use of any Plus-P .38 Special loads you may want to choose. A similar S&W Model 10 won’t. I have a deep affection for the Smith & Wesson, but I have no illusions about what it will or won’t handle.