I am assuming that not everyone reads the comments left to posts on site, so I thought it best to bring this to your attention via a new post.
Ian has left a further comment on the post referring to "Machin Self Adhesive Cylinder Blocks": (again many thanks Ian) with this information which we all may have overlooked.
"A friend sent me the layout shown by Dave on the Machin Forum. One thing I think should be made clear at the outset - the fact that there are six different 'sheets' on a cylinder does not mean that there are 6 half-sheets and therefore 6 different cylinders for each value.
For a start the diagram shows 3 sheets of 50 (IE 6 half-sheets of 25, the same format as the Christmas stamps).Commemorative stamps and last year's Country Definitives (apart from England) were printed with more than one value on a cylinder. For example the Wales 50p & 81p were printed side-by-side both with the same cylinder number.
If you look at the margins of special stamps you will see a similar grid with one block shaded showing the position of the sheet from that cylinder.I expect the 1st & 2nd class stamps to be printed three sheets side-by-side, which may mean three cylinder numbers D1A D1B D1C ? But it seems more than likely that one cylinder will produce £5 £2 & £1.50 stamps in three sheets of 50, each with cylinder D1, each with two panes of 25.
The marginal markings will include the grid showing, for instance, that the £1.50 uses the two panes at the left, the £2 the two central panes, and the £5 the two panes at the right. This is just a guess, but it is very likely.
Smilers followers will be aware that the small 10-stamp Smilers For Kids sheets were also probably printed with two different designs 2-up, which is why the sheets of 20 were not simply uncut sheets of 2x10.
Economical printing means a long run with three different values, rather than three short runs which contain three sheets of same value per cylinder.
(I'll be happy for somebody else to post this opinion on the Machin Forum.) "
Ian, I will be only to happy to post this on .....Roy
Posted by Ian - Norvic to Machin Mania at 12-Jan-2009 03:27:00