Is the serial number composed of numerals only, or is there a litter like V, C or K in front of it? The letter may be separated by several spaces. (There probably won't be a C or K, because those numbers would go on model-marked guns, and you say you don't see a model number.)

Look at the side of the barrel. Does it say ".38 S&W CTG" or ".38 S&W SPECIAL CTG" ?

If you could post a photo, that would help a great deal.

I'm thinking you probably have a .38 Military & Police from the mid-1930s, but the extra info will help exclude other possibilities.

__________________
David Wilson