Piecing the triangle squares was no problem but as you can see piecing those strips to the center rectangle of the faux leather was a problem. The vinyl tends to stretch and I could not even pat it flat so ripped the border strips off and cut a new piece and managed to save those border strips to use again.
I decided part of the problem was that I need to put a spacer between the border and the center rectangle so all the vinyl pieces could lay flat along those seams. I decided to cut the center panel smaller so I could add a spacer strip of plaid fabric between the center panel and the triangle square border.This time I decided to transfer the tree design to the vinyl before I stitched on the borders. I tried numerous ways to mark it and nothing seamed to work. The only thing that did work was a chalk wheel and that would brush off quickly. The only way I could come up with was to use Golden Threads quilting paper so I traced the outline of the tree and hills and used a glue stick to adhere it to the vinyl so it would stay put. I followed the outline using my sewing machine and the thread I planned to quilt it with. After stitching I torn off the paper as I will eventually quilt near these lines and add many more lines to give the trees and hills the texture it needs and sure didn't want to be picking out tiny pieces of paper out of all those lines. Did have a panic moment when I realized I cut the center rectangle smaller than it was supposed to be. Whoops! Actually it worked out that after adding the spacer strip I just had to add one more triangle square to make it fit. Of course that made the number of triangle squares an uneven number so decided to make the pattern offset and actually I like that look better now anyway. I did use those small clips to hold my seams as I stitched since I couldn’t pin the vinyl and that worked well. As you can see the center section fits the borders so much better than my first attempt. Also notice the offset triangle border setting.