At the end of the weekend I figured that I should probably fix the hole before it got any larger so I took some pictures to show you what I did.
I didn't have any of this Briggs and Little yarn left in my stash but I was able to find a bit of red sock yarn to use.
I pulled out the loose bits of yarn to find the four stitches - 2 on top and 2 on bottom that needed to be joined together. I just used darning needles to hold the stitches.
With these four stitches I just did a simple kitchener stitch to pull these live stitches together. As you can see, it does leave a tiny gap on the side but you have two tails to weave in so it is easy enough to pull the gap closed.
a view from the inside
The finished mend job. Almost as good as new.