I fear that attempting to tie all the workings down may be even more difficult than you imagine,John. Through correspondence with Harry Knox,it has become clear that crew rostering,on the one hand,and loco. rostering,on the other,were not always the same. As you say,Harry lists the 3.XXpm up ex-Perth as a 64B working but it was quite definitely 63A that provided the loco. in the period covered by his book. (And,if I had a fiver for every time I saw 44720 or 44721 on that train,I might have been able to buy one,or both,of them on withdrawal!).
As for the 6.40 up ex-Perth,I suspect that the "Princess" working referred to by our 62C correspondent might not have been a "one-off". Early in 1962 I was commuting daily across the Forth in a service provided by the Admiralty (as it then was) for staff working at Rosyth Dockyard. Our N-bound crossing often co-incided with the 06.40 as it made its way up on to the Forth Bridge. Even from a distance,it was possible to make out the loco. type (though I wasn't close or expert enough to distinguish between a Scot and a Rebuilt Patriot). I can recall seeing a "Princess",but cannot now say whether it was only once.
We've sure breathed some life into this thread!
DR