About 40 years ago I used to supply vibration monitoring instruments for rotating equipment under contract. I copied the equipment manufacturer's shoulder bag and bought 2 more secondhand instruments. The shoulder bags had a tough canvas like exterior (plastic like coating on the back side so water resistant) and a strong silky like cloth interior with 1/2" foam from a camping/sleeping mat. These were used in an industrial setting for years. I had no damage to my equipment due to drops, etc. Just from users that twisted off cable connectors. Materials were bought at a store that supplied materials for camping gear, etc.
Edit: Remember the name now, "Textile Outfitters". Of course it's gone now, but the name may trigger store names to look at