Hiya Mr J. I'm just using what we call 'Uhu' glue, which is intended for paper and cardboard. It's similar to what used to be called Bostick, a sort of all-purpose glue. Once it dries it leaves a good solid bond, and any bits of glue that show up on the interior of the room I carve off with a scalpel (apart from round piping which is too delicate). Unfortunately the nearest paint I can now get to the original Humbrol 67 grey (which is now much darker than it used to be hence why I can no longer use it) is one intended for model railway locomotives, and unfortunately is is a satin finish. I'm hoping with the low-lighting levels I will again use this difference will be hidden somewhat.