Hi Jon, I'm new to this forum and just scanned through this thread. Honestly I think you are going to take a beating on the car when you try to sell it. My brother had a highly modified 90 LX a couple years back that he took a huge hit on because you will never find the perfect buyer for your car. For the 10k you are asking most would rather have a Cobra or 99-04 car. I think your car looks great but you never get that money back in resale. Truthfully your car would probably be worth more if it was stock. My LX had a fully built engine, 5 lug conversion w/ Brembo brake kit, cervini cowl induction hood... easily over 10k invested and lost it for 6k. Like others have mentioned it sucks to own a 1994-98 Mustang because most people prefer the 99-up cars. I personally like the look of a 96-98 Cobra more than my 03, but most are not like me. I have a good friend who has listed his Atlantic Blue (rare 1 year color) 1998 Cobra with only 35k original miles for sale for $12,000....his car has been on autotrader for over a year! His car is probably more desirable to most than yours.
I suggest that you part your car out, sell it piece by piece, it may take longer but you will get more money back. I for one would be interested in several parts, Dez Racing tuned my Cobra they do excellent work!
As far as those telling you about the problems with the 03-04 Cobras, don't listen to them. The IRS issue is highly overrated, once you own the Cobra mods are super-cheap. My cai alone gave me 30rwhp! The mods on my cobra are fairly minor and Dez tuned it Conservatively at about 440RWHP, 70RWHP over stock! Not sure how true it is but many claim that 04 model Cobras and Mach1s tend to dyno at more power...
Good luck with whatever you decide to do, but realistically I think 6-7k is the most you get and that's being very patient waiting for a buyer.