Reference/ registering of Music memorabilia?

I know there are a few music collectors and completists who use this forum, Does any one know of a site for registering newly discovered items? or maybe gets quotes on the rare items?

Is there some sort of massive online catalog or ways of authenticating items?

Hopefully I've made sense.

Thanks

i don't get exactly what you mean, but Popsike is good for vinyl valuation and some other stuff.

ok, sorry about that haha.
But yeah I'll check that out, thanks Lee.