The 2011 new tariff stamps included 76p, £1.10 and £1.65 printed side-by-side on a single 3-value cylinder, with a 68p printed in three columns on a single-value cylinder. (The stamps are shown on our website.)
Further printings took place through the year including 10/01/12 all with the M11L year code.
Later in the year, it became obvious that Royal Mail would not be able to change postage rates again at the end of March 2012, and that the announcement of new rates and implementation of the change would be delayed. A further printing of the much used 76p (airmail letters outside Europe 10g and worldwide postcards) was necessary.
This printing took place on 25/01/12 but despite the fact that the grid showed this to be a 3-value printing (as above), the £1.10 and £1.65 values were apparently not placed on sale at post office branches, and they were never on the date/cylinder list provided to dealers by Royal Mail Tallents House.
However we have now been sent a scan of the two values from that printing. Sheets from this printing are not, as far as we know, in the hands of any collectors or dealers**, although it has been suggested that they may have been obtainable from Royal Mail's online shop. However, as the values ceased to be available there with effect from the introduction of the new tariff when they were replaced by the £1.28 and £1.90 values, I find this hard to believe.
It made economic sense to continue to use the D1 cylinders even if a new iridescent M12L cylinder was needed, even if it meant some stamps would never be sold. (Indeed if what we now know was correct then, that the year code depends on when the contract was placed, which would explain why the 10/01/12 printing had the M11L code.)
But if these stamps from this printing were made available to anybody, then they should have been made available to everybody. If they were sold from Royal Mail Direct (in Edinburgh) then they should have been available from the Philatelic Service (in Edinburgh). After all, the Philatelic Service stands to profit from sale of stamps which won't be used, so it makes much more sense for Royal Mail to sell them to collectors. The gap between the left hand and the right hand seems to be one into which any number of stamp printings could fall.
If anybody does hear of the £1.10 and £1.65 M12L stamps existing with collectors or dealers we would be delighted to know more, and we would protect our sources as always. Do let us know.
**And note: we do not have any of these; and to the people who read about them here and then go to Richard P in Norwich as their usual supplier, he doesn't have any either!
Following the comment regarding scans of the iridescent code on the above, I'm adding the 76p image which we know came from the same date's printing. The iridescent cylinder is one cylinder across all three columns so they must all be M12L.
(To wrap up the story so far, eventually an extra single-value printing of the 76p from cylinder D2 was made on 30/03/12.)