It doesn't look like a contract reject, but rather simple a period commercial first model in .44 Russian. The thing that is throwing everyone is the serial number which doesn't appear to be original. If it was 13667 it would make more sense. It appears to have the early square ended trigger so it wouldn't be later than about 19000. At 3667 and a contact reject it would more likely have full serial numbers, not assy numbers and more likely a sraight frame.
Nice revolver!
Joe