This might be a long way around. But in the Express tools there is a utility to change space. You can take items from modelspace and put them in paperspace or vice versa.
your text is in PS @ a scale of 1/4". In the end you want your text in PS but at a scale of 1/8" correct?
If you do a saveas to your drawing as a test. Change the space of your PS text so it is now in MS. change the scale on your viewport, then change the space of your text back into PS. In your case because you taking text(roomnames) from 3 different drawings, you will have to change them all in MS, then combine all the text into one file and the change it all back in PS. I don't know what exactly will happen when you change the scale of the viewport.
I have seen lisp's that will rescale a block upon it's insertion point and if your room names/numbers were blocks you could use this option either on it's own or in conjunction with the change space.
Pieter