It is a MOT fail or should be if the MOT tester is doing his job correct to pass a car that as had a high level/ third brake light that as been converted to a rear fog light.
Converting the right hand side reversing light is more than ok for MOT’s, although they do prefer a proper rear fog light stand alone.
And just as a foot note guys,you don’t need reversing lights for MOT’s, if you don’t have them it is still a pass.
That makes 7,500 posts.
M-m