Big John overall Jean jumper

Excellent vintage condition. One of a kind piece. I believe this was altered by someone who is very talented with sewing. I cannot find another one like it online. No interior tags. Slit up the back. Please see measurements to ensure a good fit. Waist measures 14.75 inches across laying flat. From the strap to the hem it’s 46.5 inches long but this will vary based on the adjustable straps.