[DTV]

Maybe also a new studio B style desk to replace the old one. Those are the only changes I can envisage being done within a short time window. Additionally, any new desk could potentially be moved into another studio in future if C was mothballed.

No way would you be able to fit a Studio B-style desk on that rostrum. The diameter of the outside edge of the new Studio-B desks is about twice that of the diameter of the old 2013-style desks and not much less than that of the old Studio C and E rostrums. Even if you removed the printer/storage unit, it'd still be too tight to fit in a chair - plus it'd just look horrendously out of place. Towers might also be out owing to the fact they seem to need quite a sizeable footprint for stability and there doesn't look to be too much room between the current base of the plasmas and the Furio tracks.

Also not sure how much substantive work could be done to C without dismantling a large part of the set. The stage door is behind the right-hand lightbox wall - without taking that apart, it would be very difficult to get sizeable set elements in or out of the studio. Even if you could get it through the regular doors, they aren't exactly positioned in a way that would make it easy without dismantling other set elements.