Honestly I dont think it will be worth it. I am selling my 89 gsxr 1100/1216 that has about 9-10 thousand dollars into it. It has a built motor and has been rebuilt from top to bottom (I mean everything).Alot of chrome/polish and I am asking 4500 (would take 4100) which is less that half of what has been put into it. I have had a few calls but nothing serious. It takes someone looking for this kind of bike to appreciate the time money that has been put into it. Most of the sportbike riders are younger (not meant negatively) and want the latest greatest thats out there. I personally like your bike (the Z) and appreciate what it takes to make a bike like this. Good luck if you do decide to do it.