Vintage Levi 501 jeans 1986 rare no back tags single stitch shrink to fit sz 11

Size tag says size 11 Actual measurements: Waist 13.5" across Rise 12" Inseam 28" I can't find others identical to these. Here's what I know, the inner leg stitch is a single stitch. The tag inside is a paper tag and when lifted up has a year '86 on it. The style tag inside says 26501. What's rare about these however is there is no tab on the back or any back tags. No hint of them originally being there either. From research I've found it could be part of their signature line, which in that case I still can't find any like those for sale either. These jeans have been cut at the ankles for a raw hem, the knees have fading but other than that for being close to 40 years old these jeans are in good shape!