Headshell mounted cartrige storage/protection

Curious what the best options are for storage/protection of single and multiple bayonet style, headshell mounted cartridges?

I have factory cases/boxes and a Fidelity Research case that holds 2 headshells but looking for something that holds more.
I know there are vintage FR cases that hold up to 5 headshells but how well has the foam and rest of box held up?

Looking for quality, not a cheap plastic 'DJ' case.
I think you are going to have to make your own.   The only ones I have ever seen are the Fidelity Research ones.  I think they were FR - it was a long time ago and I haven't seen any since.
The K-5 cases are available on EBay and HiFiDo (under Accessories but be quick to pounce) and you can sometimes find the 10 cartridge holders which were made by the company that originally made the K-5 for Fidelity Research.
The internal foam is very rugged if it hasn’t been abused.....
Search in ebay:

EMJ cartridge keeper

Nice looking storage for multiple cartridges