Hudson,
there are several websites where booksellers can upload their s/h stock for you to search. The one I use most is Advanced Book Exchange (actually based in Canada), and they do indeed have a copy of the 1973 reprint listed -- location Carnforth, Lancs. You can also register what you are looking for and have email when copies turn up. As these sites themselves do not sell anything (to the public anyway), I hope this is not deemed to be advertising.
Should be enough info here for you to track it down, PM me if not.
ab