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 been done before but hard to scale as a standalone business

for ex, https://techcrunch.com/2022/03/09/public-buys-otis-bringing-fractional-ownership-of-alternative-assets-to-its-platform

need to answer what’s unlocked by being onchain other than short-term swap fees