It's been sitting in a drawer for years, I assume it's a 1910 model since it's stamped 1931. I know the preferred action is the 1936 with the cocking piece knob but is that the only difference between the 1936 and the 1910?

Gas venting is the only real difference as far as the action is concerned. The later 1936's were vented on the bolt face, extractor, and receiver.

Thank you.