Mp40 trigger switch

I've had no problems from this for a while, so put off changing over the trigger switch to a micro switch, not an overly hard job, but takes a little while to set up. Now just days before the battle the old mp40 decides to throw a hissy fit and now have intermittent firing.
That will teach me to put jobs off for later! No real problem as only being a back up weapon, but it's now moved up on the " to do " list. I like this piece of junk, but that's what it is, after this weekend this will get a complete strip down and do every upgrade job I've been meaning to do for months.
Andy