I can't say I'm an expert, but... Now that the remake exists (everyone on here knows about it) selling an original one means it either has to be cheap(er) - e.g. a players condition or above average but not mint, and priced accordingly - or a super minter that has had no expense spared on it.
You should include photos of the boards, backbox photos, a lot more high res photos of the playfield, etc. It should read like it's a cherished example, not something that - with respect - it sounds like you've stumbled upon.
In my humble opinion you'll never get close to £6500 for one on here unless it is immaculate, and even then it's a very limited market thanks to the remake.