I was a recent Branfordite. Senior member of BYC. Formerly Barbcat NS30 #170
If you can get the starter out and in hand, I am sure the counter clerks can
find it. W27 or relatives are Mitsubishi marinized tractor and pump engines.
Give local Napa a call. Last I knew they were Exit 54 I95, less than a mile north.
First of all, Peter, I'm not sure you need a starter. Lots of things need to be checked first. If however, it is a starter problem, it may just be the solenoid. The best thing to do is find an auto electric shop and have them check it out prior to replacing it.