JOBO 2520 Extension for use with Uniroller/Beseler Base

I got tired of using a hand roller for agitation while developing sheet film in my JOBO 2520. I have a beseler rolling base but the 2520 is too short to fit on both wheels. This is a basic extension tube to attach to the bottom of the tank so it can fit across the whole roller.

I modeled indents for round magnets up to 14mm diameter with a thickness of 2mm. I originally super glued the magnets to the bottom of the JOBO but the glue didnt hold. For now I am just using a strip of gaff tape but I plan on finding a waterproof epoxy to attach the magnets again.