I was brave with these and decided to try my hand at a bit of intarsia on the top part, in order to make the border all navy, both because I liked the navy border at the bottom and also because I knew I would not have enough of the tweed to finish the entire thing. It ended up working out perfectly, yarn-wise, as I have 2 g of the main color left over! And I'm pretty proud of how the intarsia turned out! All in all, a fine idea, and I could not be more pleased.
Some notes on doing the intarsia. (Hopefully this makes sense.)
I started with the navy on the last decrease round before the garter stitch sections (the row that ends with 76 stitches). I worked back and forth until the side bind off, beginning and ending the row at the back center, so I had three bits of the main color and two of the navy going at once. After I bound off the side stitches, I sewed up the opening in the back and continued as in the pattern. It was not difficult, and it looks great. I probably could have increased a couple stitches in order to leave more room for seaming that little bit in the back, but it really wasn't necessary, and the seam is barely noticeable. On the back and the bib, I did the first and last 4 stitches of every row in navy and the center stitches in the main color. I switched to all navy on the bib two rows before the buttonhole row, and on the back I switched on the last decrease row.
I also used the gusset and short row instructions found here.