Re: Technical question re: old load handgun kept in storage
Except for the old Remington double derringer (in .41 caliber) and the Model 51 auto pistol, there were no Remington handguns being made in the era you have chosen. I think your idea of an S&W swingout cylinder revolver in .38 Special is more realistic. By the late 1930s around 3/4 million had been made so they were quite common.
There are some oddball exceptions, but usually revolvers don't have safety catches; to have an S&W revolver with a safety would show ignorance.