Thanks Craig, now that I look at the pictures and my pump, I can see it would take some additional plumbing modification beyond dealing with the no return line. Since I just want to get back in the air ASAP, I ordered a bare pump for less than $70 off of Amazon. Since it's a standard automotive part, I may as well find it from the quickest and/or cheapest place (in this case, probably both with 2 day shipping).
By the way, I removed it from the airplane tonight and played around with it using a spare battery. For whatever reason, it's locked up. I only hear a slight click every time I give it power.
RV-8A Flying since May 2009, 300+ hours
Mattituck IOF-360, WW 200RV Prop
Past President, EAA838 Racine, WI