The new stamps use cylinders D1 and the stamps are in guttered sheets of 50 with two panes of 25. Dates of printing known so far are
19/09/12 and 20/09/12 for the small 1st red, and (updated 15 Jan)
24/09/12 for the 1st class Large.
The 1p - 20p stamps have been printed with an iridescent overprint for the first time. The cylinder numbers used are D2 for the colour, and D1 for the phosphor and iridescent overprint. The sheets are of 25 (5x5) as before. In this new printing all the stamps appear to be printed in all 12 grid positions on the cylinder.
Printing dates seen (and there may be others) are:
2p & 5p 12/09/12
10p & 20p 13/09/12
The 50p and £1 stamps are also in sheets of 25, with 12 grid positions for each. Cylinder numbers are D1 x3. Colours in these pictures are darker than the stamps appear to me (the 50p shown here looks very blue). The £1 is very close to the colour of the engraved £5.
Printing dates are 18/09/12 for both values.
The booklets are very similar to the previous versions with security codes MSIL for the book of 6, MTIL for the book of 12, and MFIL for the book of 4 Large.
Booklet of 4 x 1st Large - cylinders W2 W1 W1
Booklet of 12 x 1st - cylinders W5 W2(p) W1(i) - correction
Booklet of 6 x 1st - no cylinder booklets received yet.
12.12.12 Richard has found some cylinder booklets showing red cylinder W6 (cylinders for phosphor and iridescent not yet confirmed). Note that the cylinder numbers on these booklets is obscured by the front cover, being printed further to the left than on the other two booklets.
BUSINESS SHEETS and COILS - not yet received
UPDATE: for those who have asked, here is a comparison between the original 1st class flame and the new Royal Mail red>