Decimal Machins: Essays, Proofs and Trials: 1972 cancellation ink colour trials, Machin 50p. and 20p. on two f.d.c’s with “SPECIMEN IMPRESSION” circular cancellations, ms. “18/5/72” approved notes, also four f.d.c’s with no adhesives but with “CANCELLING INKS/FOR PHILYMPIA” handstamps and the same circular cancellations in a range of colours. (Image1)

Decimal Machins: Unique laboratory report dated May 18 1971 and headed “Removal of phosphor overprints from U.K. postage stamps” with conclusion that “the method reported and as carried out here does not produce acceptable non phosphor varieties”, produced for Aubrey Walker, chief chemist of the Post Office Research and Quality Division, with sheets 5, 8 and 9 of 16 from the supporting pages, each on Post Office Purchasing and Supply Department headed paper with a range of imperforate Machins (fourteen on each sheet) each handstamped “MATERIAL SECTION, STUDD STREET/ISLINGTON N.1.” in violet, with sheet 5 treated with trichloroethlene, sheet 8 with acetone and trichloroethlene, and sheet 9 with butanol and ethyl acetate. This report was undertaken after Barbara Baker of Stamp Collecting Ltd claimed that non phosphor varieties could be created. Photo. (Image1)

Decimal Machins: ?Large print of Machin head in ochre-brown denominated 4p., on OCP/PVA paper (206 x 258mm), some creasing and tear but unusual. Photo. (Image1)

Decimal Machins: Essays, Proofs and Trials: 2012 Diamond Jubilee 1st imperf. gutter block of eight from business sheet, printed by Walsall, sold as a proof but possibly a sheet removed from production due to missing yellow colour needed for Royal Mail logo. Photo. (Image1)