ripdotfun seems so obvious, surprised nobody has done this before? real physical collectibles, but the trading is digital - most collectible owners whose primary purpose is trading/investing don't care for storing physical inventory on their own anyway. 

main risk i guess is you're trusting the team for safe storage. i remember stockX was planning to do this with sneakers but didn't go through with it.

actually this has been done for a lot of one-off drops back in the day, just not generalized into a product.

unisocks comes to mind , zein was doing lots of digital + physical NFTs , there is also

unisocks comes to mind , zein was doing lots of digital + physical NFTs , there is also https://www.dyli.io/