Damn son, that's one big nut you got there!

Ahandy product is a can of 3M 77 adhesive - let's you make your own sanding bars. Also, you can cut sand paper into strips and apply them to the "L" bracket for use as a long sanding bar to straighten pieces of balsa - like 1/16 x 3 x 36 - ya run it back-n-forth against the long bar and one side ends up straight.