Tony,
I think you're right about not being able to buy that pump locally. I went to O'Reilly's and checked Richard's part #58-126. That's a pump for an early 235 (two holes in the block, covered pump back) (I have a '57 engine in my '49. It has the large hole in the block - exposed pump back) I had my local guys searching frantically for the pump like Carter's & Patrick's sell to no avail. I'd like to know who's manufacturing it. The $$ is a bit steep.