Jason, let me start by saying that I am not a market expert on the Plus 8 and therefore, you may have priced it very well; however, equally, it was your Dad's car and thus I think you may struggle to be impartial about it (I know I would be!).
I was at SGT recently and they had 3 Plus 8s, ranging from mid £20ks to low £30s and those were dealer prices and prepped cars (2 of them were low owners and low miles). So, perhaps, and I say perhaps, your car is on the high side?
Also, I would also question whether the colour change is putting some potential buyers off? If you are going to ask at the top of the market, people will be looking for investment potential, or at least strong retained value; therefore, they will be looking for originality because that is what collectors want.
Have you spoken with any helpful dealers to discuss market values?
