OK, here are some pics of my sweet little Cobweb (1/24 scale) after the operation :-) . One can still see the mistake, of course , but it is not really a problem , the house is accessible and can be viewed quite well.
That so-called "slate"floor was made by scoring, painting and satin-varnishing cardboard. Eccept for cutting the whole carboard to measure fit in, no hard measuring etc. I always prefer to do things the easy way !!!
And now the fun part- furnishing , decorating ( and, I hope, some dolls!!)