Thanks for your input! No worries about reviewing the links, I know that security is a big concern for forums like this. I just thought the pics were important to understand the crack.

I would like to attempt to repair the pump housing if the alternative is a new housing/motor anyway. Can you recommend a putty to use, and is a die grinder really necessary or could I use a regular metal file or rough sandpaper?

Replacing the pump may be a challenge as the info for the motor has long since worn away by the elements and my late father is the only one who would know for sure what HP it is. It is a 20'x40' in ground pool, ten feet deep, piped with 1.5" plumbing and a Hayward Perflex EC-75 filter (brand new, replaced an old EC-60 this season).

Thank you very much for your help!