I contacted MDT who immediately sent me another mag catch lever, and a spare spring, mounting pin and a temporary pin to use when fitting it into the chassis, this arrived in about 5 days but unfortunately didn't cure the problem. However, it did give me a spare catch so I took a Dremel to the original!, roughed it up then added 3mm of structural epoxy (Milliput) to it, then filed it to fit, job sorted.
Meanwhile the nice chaps at MDT went above and beyond and had 3 new catches specially made, one each at +1 +2 and +3mm above the original length. They arrived today (6 days from Canada) and again each came with all the extra hardware for fitting.
Outstanding service and a joy to deal with
