I think the washer is likely the flange edge portion of the original axle pin, and that for some reason - maybe the pin diameter is too small and so the flange was taking the recoil impact, or maybe the recess for the axle flange was machined too small
the axle pin on most/all mauser parabellums 1970s issue is same as the typical P08 issue except that the flange diameter is a larger diameter similar to the 1916-17 navy lugers and the matching receiver axle recess is larger to match the pin
so it looks to me like what you have on your MP is an axle pin with flange fractured loose into a washer like part - and the burr on end of the pin is a piece of the original integral flange that remains with the pin
Ive seen one or two MP lugers with partial fractured flanges but never a washer effect like this one s
does your canon assembly show any signs of excess clearances?
or excessive wear from toggle barrels sliding upward on the frame recoil ramps ?
lugerdoc may have a replacement axle for your MP
Tom Heller POB 398 ST.Charles, MO. 63302
Tel 636-447-3006
lugerdoc@charter.net
thanks for pictures
Bill