6 x 1st class deep scarlet MSIL retail booklet reprinted with M17L year code on SBP2
This booklet appeared around the same time that Royal Mail issued the Machin 50th Anniversary booklet, which also has stamps coded M17L MSIL; that booklet was available on new issue distribution from the bureau, and was printed on SBP1. This printing of the Padlock booklet is on SBP2.
Printed by Walsall Security Printers, source code MSIL, year code M17L.
The SG catalogue number is expected to be MB18 as used for previous years.