Digging thru my pile of parts watches I found this 1961 Royal Clipper that had a severely rusted tension ring. I had previously tried to work on it but but could not get it out of the case. I finally gave it another try and was able to get the movement out. I was able to remove a whole bunch of rust dust from the movement. After a service, polish and relume of the hands it turns out it is running quite well.
This appears to be a 1961 Royal Clipper with a 10KT Yellow RGP case and case back. The back has a M1 date code. The movement is a 11ANAC 17J with a M0 date code.