Correct me if I am wrong but there appears to be confusion here, as far as I am aware there is not any specific requirement on an MOT that the car HAS to have a cat, only that it must pass the emissions test levels that woud be applicable IF it came with a cat in the first place.
i.e late spec cos with cat removed, passes an emissions test=legal MOT

I did hear of talk that they were going to change the regs so that it specified there had to be a cat fitted, but I thought that was all hear say???