R.W. Symonds, Thomas Tompion, his life and work, London, 1969, pp.147, 194, 214 & 280, figs. 114, 175 & 211
The present clock, 42 is a fine example of one of Tompion's early timepieces, whose large backplates filled out the the back of the case and were engraved by an unknown engraver whose early work was some of the best to be found on Tompion's clocks.
The position of the punch numbers on the backplate is another interesting feature. It seems that Tompion began by numbering his very earliest bracket clocks at the top left corner of the backplate, amongst the tulip engraving, in the same manner as on this example, and then started to use a larger set of punches which he put at the base of the backplate. This subsequently became the norm. The present clock was probably on the bench, having been numbered at the top left, when Tompion decided to change the system.