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.

It’s a good business idea and you could potentially then do fractional reserve collectibles whereby you issue more than you actually have hoping your customers won’t redeem them all at once hehe