Please take the following comments solely as an attempt to help you sell this car. I have read your eBay listing. It seems like this car has had very extensive work done to it. I wish I was in CA and could drive it. I bet it is a blast.
In order to clarify some of the items in your listing however you may wish to consider some revision. It is a
Series 4 (S4 or SIV) Seven not a
Mark IV. I would not call this a "Genuine... Twin-Cam model" as it no longer has the twin cam engine. This is JMO but the more accurate your listing can be the more likely the car will sell.
Personally, I hope it sells for $75,000

. Good luck.