Super!!!! Looks like it should. Don't wrry about the durability of the top coat. The thing that is a little strange to get your head around is that it's COSMETIC, strictly for looks!!! Your'e right, easy touch up. After I finished my frame, there were a few scratches in the top coat (that primer sticks like glue to the zinc!!) from running the lines and bolting things on, etc. etc. I just touched them up and it looks like it did before. You'll be able to do that anytime. The real protection is PERMANENT, it's the zinc and that will never stop protecting the frame, top coated or not. Doesn't get any better than that.
Now, make sure you have 5/16 tap handy to clean out the 4 or 5 holes that take those bolts. You might also need to use a coarse or fine "rat tail" file to clean the few other holes for thru-bolts, like the front lower and all rear control arms. I didn't but some do. Other that you shouldn't have any issues because of galvanizing. I thing Tom Parsons had to ream his emergency brake cable "thu frame holes" on his GTO frame. I cleaned mine with a file just in case. Worked great.
The best thing is that you can do the rest of your project knowing you started the rebuild with a first class frame job!!! Congratualtions on a wise decision.
Let me know if you guys have any issues and I'll be glad to help. Just PM me.
Herb Goodfellow Sr.