Gunze Super Clear is hotter than Tamiya TS13 and I've also had it react badly with the underlying colour coats - although in my case these were Zero acrylics. I have three cans of it that I'm now scared to use.
Beautiful model! I share your love of Lincolns and black is perfect for this one. (I'm working on a black Jaguar at the moment. Not the easiest of colours to work with but at least touching up small mistakes is easy - black is black.)
I just remembered that Juha Airio from Finland once did a magazine article where he did the same car in the same colour. I'm 100% sure yours will be just as beautiful.