Hi Paddy Wyn...

It has taken me a couple of days to get back to the board...but here I am.

I haven´t tracked down the buses to Factory. But the buses that go to Las Rozas Village are the interurbanos (green buses) numbers 625 and 628. You get either of these buses in Moncloa (take the Metro to Moncloa) and head to the intercambiador de autobuses (on the lower level). The buses depart from different "andenes" so you will have to check the red posts carefully for either of the routes. Generally they run every 15 to 20 mins.

Will look into Factory for you!