There are plenty of rebuilt pumps available, and they're not too expensive. Unless you have a full machine shop and a lot of experience, don't even think about doing a rebuild. It requires a press and some specialty tools, and repair kits are just about nonexistent. The same pump fits about a 25-year span of stovebolt engines, all the way up to the 1954 model 235 and just about all the 216's. The only difference is the width of the pulley on late model 216's and 235's.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!