RAF switch from Type B to Type C on upper wings.

Hi All,

I have two irksome queries flying around in my head at present,

1. When in ’45 did the RAF start applying Type C roundels to the upper surfaces of aircraft wings? I know it was in ’45 but would appreciate a more specific date.
2. Did this change apply to all aircraft or was it only to certain types? If to all types did this change take some time to come into force or did it happen relatively quickly.

A third question if I may (I lied about only having two!!!) In the opinion of the forum members would you consider it likely that a support squadron (target tugs) would have made the changes to their aircraft by August 1945?

I am referring to aircraft in the ETO rather than the MTO or the Far East.

Thanks in advance for any info that you can provide.

regds

Colin