I've found what I feel is the best washer size for squadron positioning is:
- 1" + 1/8" OD (outer diameter)
- 1/16" thick
- Washer with a hole in the middle for the small protrusion at the bottom of the squadron's base to fit into.
These washers fit into the bottom of the base with no exposure. The washer is fully contained within the base. The diameter of the washer is slightly smaller than the opening in the bottom of squadrons, but it is easy to put a squad over the washer. I would say there is maybe 1mm of play when the washer in under the squad, so there isn't a lot of room to spare. I plan on painting the washers in Imperial blue/black and Rebel red, possibly numbering them too, but I'm a little concerned the primer/paint/seal layers may make the washer to big for as quad to put over it. I'm going to create 2 prototypes to test this.
I couldn't find these locally so I ordered them online at the following link. Unfortunately, the minimum # to order # is 100. It would be a good purchase for an Armada club to buy together and split. The total cost with tax and shipping to Western New York was 20.59, so that comes out to 21 cents a washer.
Link:
https://www.grainger.com/product/FABORY-5-16-x1-1-8-O-D-22UH02