Marc
You might want to try to contact the Rapier registry
http://clubs.hemmings.com/frameset.cfm?club=sunbeamor post your question to the Rootes section of the SAOCA forum
somebody will have a definite answer.
www.saoca.orgYour engine is a 1492cc motor right? It would be the same as a Series I Alpine engine (except your head would be iron). Even so, oil pump parts are getting scarce. The distributor probably could come from any 1592cc/1492 Alpine.
Is the pump totally a mess? Can you just clean up the faces of the stator and rotor?
With all that said, if you aren't too far into your rebuild and you don't have an issue with matching serial numbers you might consider going to the 1592cc engine or even the much later 1725cc Rootes motor.
Steve