I have a Standard Arms Model M that I'm trying to disassemble to clean. The action handle - that pretty decorated brass pump handle - is held on by a pin of some kind. It's not a pin you can drive out. It goes from one side of the handle to the other, inside a bushing. I've seen pics online, and in some rifles, it looks like one side of the pin has a slotted screw head. The one on my rifle doesn't have a screw head, but the pin does rotate inside a cylindrical bushing.
The slide handle on a Model M is not the same as the Model G. Not much info anywhere on this rifle.
Any ideas?