Fred, I've got some doubts about your clipboard. Did you try whether a simple copy paste works or not?

I am not sure what you mean by "simple copy / paste".

I will repeat (again) what I am doing here:
I open the gallery (the model I want to copy as new furniture) and the rest.bottom model (this where the "new furniture" is supposed to go).

Both models are now open.

I go to the gallery model select all and do:
tools->copy as new furniture.

This seems to work.

Now I switch over to the ALREADY OPEN rest.bottom model and try the following:
-right click on the model panel -> no paste option.
-using "edit" does not show a paste option.
-CTRL - V does not work.

Where does sh3d store the copy as new furniture?