I have received my first supplies of the new Walsall booklets containing Machin definitives with security features. Some have cylinder numbers, some don't so I'll only be able to report what I have. The phosphor bands seem to be more or less accurately aligned on all booklets.
6 x 1st - cylinders W5 W2(P) W1 (overlay) - Postcode advert inside front cover
12 x 1st - no cylinder received
12 x 2nd - no cylinder received
4 x 1st Large - cylinders W1 W1(P) W1(o) - blank inside front cover
4 x 2nd Large - no cylinders received - blank inside front cover
As reported before, the 1st class letter stamp was first issued on 10 March in the Design Classics retail book (with the red cover). Used examples may be distinguished from the current book in two ways.
The new booklets have flat-topped perforations; the Design Classics booklet has rounded tops to perforations.
As previously mentioned on the Walsall printings the security cut is actually 4 cuts, compared with De La Rue's two cuts. On the latest (31 March) booklets the gap at the apex of the curve is wider than on the Design Classics (10 March) booklets.
Correction: The current (31 March) booklets have a wide gap on the 1st & 2nd books of 12, and a narrow gap on the 1st book of 6 and the Large Letter books.
Of course we don't know at this stage whether these distinguishing features will be consistent, but at least it gives us something to look for on used stamps.
Post Office Circulars - Here is a scan of the Post Office Circular for 28th September 1874 which announced Wiveliscombe (and Milverton) becoming R.S.O.s (towards the bottom of the...