Good luck on getting all the details together for the show. An advance hanging trial as you discuss here is a good sign you are doing the right kind of advance planning.
Let us know how it all works out.
I am intrigued on your comment that the 20x24 frames are self made.
Commercially made ones that size are $$$, so I understand your motivation.
When you are less occupied, a post on your frame making technique woukd be appreciated.