[Arran]

Dan;
  Are you sure that it's a Rogers branded set or a Canadian Majestic? From what i can tell all of the higher end Rogers brand sets got the rolling pin dials such as the 10-10 and 10-12. Anyhow the groggy performance of that 10-12 you have, the one that still has the clock, might be attributed to drifted resistors, I found a whole bunch of off spec resistors whilst rebuilding my 10-60, not to mention that crappy rotted rubber/gutta percha covered wire. It may be worth checking the ones in the Queen Elizabeth for drifted values as well, often recapping is not enough.
Regards
Arran

P.S I love how they reused the same sheet metal chassis for different models, note the three caps they put over the holes along the top right hand side of the chassis. They did that in my Deforest Crosley Brahms, on the 10 tube version of that chassis they add an extra tube, on the 11 tube they add two extra tubes and an extra IF can. It was sort of a scam though, the extra tube in the 10 tube chassis was an 84M, a Rogers copy of a 6H6G with a spray shield, and the two diodes perform the same second detector-AVC functions that the diodes in the 6R7M do in the 9 tube Brahms chassis.