The casings have now been cleaned and inspected, one of the barrel stud threads had gone which has been helycoiled. I have also found a snapped stud which holds the mag housing on luckily i managed to get it out without damaging the thread. One of the things i have noticed is that the casings were fitted with Russian bearings, seems a bit odd maybe this is common on Spanish lambrettas, these will all be replaced anyhow along with a new mag housing as there is a crack running around the circlip slot.