How much of Bitcoin Cash's value is due to legacy Bitcoin holders?

[ChiBitCTy]

I'm not sure if I've even phrased this question correctly, but here is what I am asking... In August 2017 Bitcoin had it's first hard fork, Bitcoin Cash.  So therefore any bitcoin you obtained before this date will contain both bitcoin and bitcoin cash ( of course many other subsequent forks ).  Now..a lot of people never split off  the bitcoin cash, and still hold it with their "legacy" bitcoin in paper wallets/hardware wallets etc.  I know personally the only reason I hold some bitcoin-cash is because I hold it within collectibles/paper wallets ( Like Casascius coins for example ), but if I could split it off without ruining the numismatic value of the coin art/paper wallet ( to redeem the coins you have to peel the hologram hiding the private keys, which in return ruins the value of the coins numismatic value), I would. 

So this begs the question, if everyone who only holds bitcoin-cash because they simply haven't split it off yet ..where would bitcoin-cash's value be at right now if they were all of a sudden to split it off/sell it off? Would this be a large percentage of bitcoin cash as a whole ?  Does this make up 5%, 10%, 20% etc.. of the bitcoin cash being held?

Hopefully I'm making sense here.  Kind of hard explaining this via text.