Great advice, even before you get to the primer stage. It's hard with armor that needs painting it's got to fit spot on, I ran in to the same issue with a clone commission build, had everything set to size (as we where similar) only to find the belt would not close on the recipient when trial fitted, man took some work to add in some extra but lesson learned with my FOTK build.
These do take a lot more work than an OTTK but I'm sure you'll get there in the end, don't loose faith