Thanks for the pics Larry. I use the same balancing method for small props but as I am an accident waiting to happen I kept my eyes open 'til I found a small, clear plastic box just the right size to glue the razor blades into opposite sides and still be able to close the cover to prevent 'oopses' and leakage of vital fluids. The cover is about a third of the total depth of the box. Had I been thinking I would have glued the blades into the cover giving more room for the prop to teeter-totter without having to grind a relief into the sides of the box. A piece of music wire or drill stem of the proper diameter to fit the prop hole tightly and slot into the box diagonally for storage completes the assemblage.
I really need to find a couple more boxes and build new ones with the blades in the short side of the box. As it is when I need it in the shop it's always in the flight box and when I need it at the field it's always in the shop. I think there's a natural law about such things. HTH, Tom