Help Catalogue These Great Britain 'Consular Service' Revenue Stamps

Hello, I came across these two British Consular Service revenue stamps while sorting through some new acquisitions. I have been unable to find a catalogue of British revenue stamps as they all seem to be out of print. I want to create a page in my collection for these two and the others in this particular series. My guess is around 1921 with King George V image. I'm hoping someone can help me with catalogue information of these stamps: Series description, catalogue numbers, face values, and colours for each stamp in the series.

J. Barefoot will list them.

Unable to assist without proper stamp ID
Perforation guage, Watermarks.
1989
Price around $30 freight inclusive.

PS I am having trouble with identifying yours, 8s and 10s KGV show only in Green, it may be yours are colour changelings?
Boiling hot water? Chemicals? Light damage?

ebay

Thanks Rod22, they are both perforated 15 x 13.75. Wmk. looks like Scott's #35 (SG 111) Block cipher. Are you offering the book for sale? I'm located in Ontario, Canada. Thx

Sorry Roy,
my catalogues are more important than my stamps
ISBN 0906845424

On further digesting, Barefoot,
ID is rather simple, they must be
1921 George V Key Types
Multi Orb IR, Perf 14.74 x 13.75

Barefoot #135 and 136 respectively (page 28)
Green and Blue , Green and vermilion
CV 30c to £1.50

Thanks Rod that was the information I was needing. And, I hear you about the reference material ... I try to gather as much as I can. Cheers and happy thanksgiving!!

Thank you Roy, same to you.
From my extensive collection of 4

Have a look at https://www.ibredguy.co.uk/main.php...itemId=17072

Great link, thank you.