Cameron
Good luck with the sale.
I'm not going to enter any discussion on a cars value. I think you summed it up by saying that you have interested parties - so guess you are not dreaming.
Unless it's the new project that captures your dreams.
Knowing the value of a SPF and the work you've done, I'm sure there will be someone that wants a SPF and can add the 'add ons' in and come up with the dollars you ask.
Again good luck. Mmmm would like to see it stored though and you back in it in a year or two!!!
Bernie