UPDATE:
I have been emailing and on the phone with Ultra Pro, BCW, Whitman, Capital Plastics, and various coin/memorabilia shops trying to find a product the right size to hold these, even oversized ones like the Capital 5x7 meteor cases just without the insert, I can 3D print an insert, but not one place had anything helpful to offer. My only option would be to buy the 200 or so 5x7 meteor cases at full price and just throw away the inserts. * I will add that while most every place I called gave me a pretty quick "sorry can't help ya," the nice lady at BCW customer service did try to help me find workable solutions. *
Then First Commemorative Mint came through with a Win! A very helpful gentleman over there actually went through the leg work of putting together a supplemental order from their manufacturer of just the clear case from the 1961 proof set big decorative display that they sell. To be honest I figured this would be the least likely source to pan out, and I imagine my luck in this working out has a great deal to do with who answered that call. This was customer service above and beyond answering a few questions or placing a regular order so I have to give them a shout out.
It will be a while until they actually arrive but I will get some pics up when they do.