Awesome
job with what looks to me as a form of "Darning repair", and use of Bias Tape for the corners.
I have seen new bags come with such poor stitching they come apart on the first use.
Sometimes buying Bias Tape is simpler than making it yourself, but either way it is very effective at reinforcing the joins/corners.
I love that you are still using a 'Vibrating Shuttle' sewing machine.
Is the machine a treadle, hand crank or electric and what kind is it - looks like it might be an early Singer or similar machine.
My wife is a quilter and as such I have engaged in repair/refurbish of the 'older' machines.
This includes several Singer Featherweight(221), 99's, 66';s, 128 'coffin top' machines (all treadle/hand-crank/electric),
Along with other brands from Elna to White and branded machines (Sears, Eatons, etc.
These machines just simply work well on anything from satin/lace to canvas & light leather - and easy to maintain/repair.
There is something soothing about using a treadle machine.
Great idea and workmanship/workwomanship(?)
Respectively, /phil/