1922 Self-Government Specimens

I recently came across the below Specimen pages from the Mauritania Specimen archives.

Looking in the George V study papers it states "None Issued" for Specimen examples of the Self-Government overprint sets. It's true there were no stamps overprinted 'SPECIMEN' by the printers but the below examples ¹show that Specimen stamps were issued to the colonies.

¹Update 19-Nov-2011 from James :
"show that stamps in normal unused condition were sent from Malta to London and then forwarded to the UPU for distribution as specimens."

Which suggests Malta was responsible for sending back these stamps for distribution.. does anyone have any more information on this? - he also adds :

"Of the many issues overprinted or surcharged (or printed) in Malta only the 1902 One Penny on 2.5d was distributed with a SPECIMEN overprint. The 1922 Self-Government set, the 1922 One farthing on 2d, the 1925 Two pence halfpenny on 3d, the 1926 POSTAGE overprints on the Melita set, the 1928 6d Air Mail and the 1925 (Apr) postage due stamps were all circulated in normal unused condition. This did not in any way contravene UPU regulations as is stated in the Malta Study Circle handbook."

The below examples show the 1922 Self-Government set being handstruck with SPECIMEN / COLLECTION / MAURITANIE measuring 30x14 mm overall :

For more information re the Mauritania Specimen archives visit James Bendon's website : http://www.jamesbendon.com

Whilst discussing these overprints James has asked the question which of the watermarks for the 0.5d, 2.5d, 6d and 2s were used. Just by looking at the 2s shade I've no doubt this is the Script (SG120) watermark, but can't obviously say with any certainty what the lower values would be or even if both watermarks were used and randomly distributed.
If anyone has any more details of this could they kindly contact James through his website.

For those that may be interested the above page item is actually for sale on James site along with other SPECIMEN stamps.

I had previously saved the below images that were listed in a recent auction.. I don't recall the auction or results but i include as an associated reference to above