Pics wont open (my internet really does suck!), how much of the thread was damaged? I'd say provided there is enough left to hold the nut on (and I'm afraid to say it'll be the MOT tester that decides if there's enough I'm afraid) then I'd say you should be ok. If your tester is a sympathetic bloke he might let you off if you explain you had trouble with parts and that the new ones are in transit, gotta be worth a shot?
Not much of the thread, today I filed some of the bits down and to my surprise the nut actually goes all the way and tightens so should be good to fit on Monday when I take them to a garage to have springs fitted to strut (flaming spring compressors still haven't arrived) Do they actually check the nuts on the shock that are in the boot? I thought they just check the springs for cracks, which they were?