Boss OD-1 Overdrive Pedal 1980 Made In Japan Black Label. Condition is "Used". Dispatched with Royal Mail 2nd Class.
Classic distortion pedal and great sound. The original and the best. Over 40 years old and still sounds great! OD-1D board with 8 pin JRC 4558 chip.

Listing this as parts or repairs as it has the bleed issue (when the pedal is in bypass a small amount of the distorted signal is audible and the controls can still be used)

This is not actually a fault per se, it's due to the design of the pedal, most early SD-1s suffer from the exact same problem. As such, there isn't really a fix for it other than to use some other switching system like a Line Selector, or modify it, or convert it to true bypass, but I would prefer to leave the pedal in original condition. Most people don't even notice this quirk as they are mostly used through the drive channel of an amp in the first place so it doesn't impede usage at all.

Other than this, the pedal itself works fine and sounds exactly as it should, it's just something to be aware of if you really need a clean signal, as you won't be able to use it like that.