I read about your detailed build with much interest, congrats on taking the time and making the effort to complete this piece, I only wish I had the time and skill to do the same... (I love to read stuff like this so I can learn from others & maybe one day I can build something for myself) enjoy it my friend, it's a beauty at https://canoesurfer.net/kayak-life-vest/
Update...it went for $1430.55 plus $25 shipping.
Maybe the buyer knows it is a 1520. Maybe not.