I will need to read up about that. Nora.
First time I have seen that cancel.
Usually Great Britain Parcel cancels, are rubber two ringed circles,
with name across the centre. very common.
Not sure if you would ever find info on that Leeds example.
PS: If you use text string "Sc139 great britain" stamps, or similar,
, you will see how common these stamps were used for parcels, and Registration.
Very scarce used on cover,
if at all.
There are a few there, Lombard Street, and a squared circle.
Anew one for me MR (Roller)
Yes Manchester confirmed.