Noggin Thanks for the reply.
You have confirmed what I thought the rules were, before someone seemed to have said that they had changed.
I also strongly agree with your advice, about doing the revalidation tests on a M/E.
If the weather is slightly marginal, I will sometimes fly a twin, when I would not get airborne in a single. Hence I more likely to get into IMC in the twin. So, it seems only prudent to do the IMC tests on a twin, as I have done.