UPDATE: Thanks to all who chimed in. I appreciate your help.
I ordered one "westerbeke" pump (WB-038445, $1265) and one "sherwood" pump (R10870G, $699), supposedly the equivalent. I wanted to see if they are in fact equivalent or possibly even the exact same pump. After receiving them both I can definitively confirm they are the SAME pump (because they both have the Sherwood R10870G tag on them). The one from Westerbeke isn't even painted red (still raw). BUT as some had mentioned here, the base/foot does appear to have a very slight milling/modification. It is so slight (about 1mm channel on each edge) I can't imagine it does anything required to mate with the bracket (which I believe is a completely flat surface). However, I can't check, because my
boat is
on the hard in
Mexico. Just to be safe, I'll have a metal shop mill the Sherwood pump base to copy the Westerbeke version. Also worth noting, Sherwood would not respond to my inquiry asking if they
sold these pumps to Westerbeke.
Lastly, the bolts that attach the pump to the bracket (with the rectangular backing plate) are the last part of the puzzle. They do not seem to be able to go through the holes on the pump (because the bolt heads cannot clear the adjacent pump housing). This is true on BOTH the Westerbeke and Sherwood products. They were difficult and just barely cleared on the failed original pump, but I was able to remove them. Not sure what the difference is. Perhaps I'll need to file the pump housing a tiny bit.