In the meantime thanks for all the comments on the autumn's Post and Go programme - that certainly set off a lively debate, not least about the ethics of obtaining and selling blank strips! More of that later.
The important news for now is that stocks of the 1st class x 12 booklets have at last appeared across the country and we have them in our shop, both as single stamps and whole booklets, including cylinders.
The cylinder numbers - W7 red, W1 iridescent, and a new (?*) W2 phosphor - are, as usual this year, hidden by the front cover. But the packing date cannot be relied upon as an indicator of the year code on the booklets within the pack. Our stock of booklets with M15L stamps has a packing date of 30/03/15, but we have reports that packs with April 2015 packing dates have M14L stamps in.
(* See 'Comments' for discussion on whether this is a new W2 cylinder or the old one with the number repositioned.)
We also have the 2nd Large MA15 booklets in stock now.
Aside from any sheet stamp reprints, this probably means that the only Machin definitives still to appear this year will be the MPIL M15L 1st and 2nd class in the Star Wars Prestige Stamp Book.
We now know that these will be self-adhesive, and we are reasonably certain that the 1st class will be red.