[lugerholsterrepair]

it is longer in one leg than the other(at least some are, maybe not all), and if original may only go in the side plate in one direction.

On all the pins I have seen they seem the same length on either leg. But..the end that is pressed into the bottom of the sideplate and snapped in may be burred, flattened, dented or otherwise deformed so that it will not then easily slip into the holes of the trigger lever. So even though it was once able to be installed either way..it may not after installation a few times. On many I have installed they snap in quite forcefully. The one I just checked is an Erfurt and I actually snapped it in with a hammer and drift.