Smith and Wesson began heat treating cylinders along about 1920. The S&W .38 Special cartidge was introduced for the Hand Ejector in late 1898. It was originally stoked with black powder, changing over to smokeless within about a year, but still tame enough for 19th century black powder spitting metallurgy.
The heat treating instills additional strength, but even in '29 S&W met the prohibition era demand for more power due to auto windshields and rudimentary body armour by using a .44 frame to house the likes of the S&W .38/.44, not exactly a .38 Special.
In '35 Elmer Keith, Phillip B. Sharpe, and Colonel D. B. Wesson changed the .38 power game entirely by developing the .357. To make this more complex and allow a bit more long winded rant, the Sporting Arms and Ammunition Manufacturers Institute (SAAMI) was created in 1926 to set industry standards and to quote Wikipedia...
"It is important to recognize that SAAMI changed the specifications for the .38 Special in 1972. Prior to that time the standard .38 Special was very close to today's "+P" cartridges."
It is nonetheless true that +P like pressures and performance did not arrive for standard .38 special until the 1950's, long AFTER Smith produced this revolver. That is if you exclude .38/.44, Hi-Vel, etc. as categories unto themselves.
After all that, I own a Military & Police Model of 1905 4th Change Target manufactured in 1910. The old boy has handled a few fairly stout standard ('pre '72 standards) 158 gr LSW in my hands but very few and doesn't particulary like them, expressing it's discomfort by backing out the rear sight horizontal screw. No more of THAT, then.
This weapon is now at least semi-retired but never complained a lick about 148 gr match loaded wadcutters, and will flat shoot with them. I suspect limiting yourself to similar is a good, conservative idea. No way would I feed my old pre-heat treating baby a modern defense oriented semi-jacketed +P. I could probably get away with a little of such shenanigans, but why?
I will not put myself in a position of need to use even post '72 standard pressure 158 gr LSWHP (think FBI load and Buffalo Bore, but post '72 standard pressure). I suspect that a lot of LRN loads would be OK, I just don't find a use for them. I pay attention to not just the pressure, but also the bullet mounted and the suitability for purpose of the weapon.
I would definitely set a limit at post '72 standard pressure, I would avoid jacketed rounds and IMHO the 148 gr wadcutter is a better round for all purposes, even defense than the LRN standard pressure (aka "The Widow Maker" meaning police officer's that had to use them widows). Preserve this piece of history by choosing a more recent Smith (like a 10-5) for hardcore banging and enjoy a truly fine lockwork in the context that shows it off the best.