Re: Stewart Warner 240A pumps.
In reality, you're probably going to have to rebuild them, NOS or not. The gaskets and seals will be shot after 40 years. Most used ones will have a problem with the electrical switch.
I'm in the process of doing all of this right now. You can buy non-functioning pumps on ebay for sub $100, but will then have to rebuild them. Gaskts are about $90, a new filter is about $30, and then there is plating if you need that, too.
Andrew Booth (Charley Farley) on this site is a wealth of knowlege, and has the parts you'll need. Do a quick search, and you'll get what you need. I suppose if you are so inclined, Andrew can rebuild them for you.
SPF GT40 MARK I P2265