Oh silly me...
Thanks for the advice, 'accidentally deleted' was pretty close actually...
It was late, my son and I were looking at mods, he wanted to play vanilla...
I moved the save games for safe keeping before mod de-activation, then forgot about it...how embarassing.
My apologies for having started a new thread, problem solved, but the advice did make me remember what I had done, cheers.
ps, my son is now playing vanilla on another pc, so i can leave the mod active on mine...