Naylor, Benzon & Co. were Merchants operating from:
20 Abchurch Lane,
According to a Post Office Commercial Directory of 1865 they were, at this time, trading from:
32 Nicholas Lane,
46 Brown’s Buildings,
1868. Unofficial underprint type 43 (over the gum) in black.
Note. Plate 147 is currently unlisted by Stanley Gibbons with this underprint.
PP143A 2d blue (SG 46 or G3)
Note. Plate 7 above is currently unlisted by Stanley Gibbons.
PP144A 4d vermilion (SG 94 or J58)
PP145 6d violet (SG 109 or J77)
PP145A 1s green (SG 117 or J105)
PP146 5s rose (SG 126 or J121)
A single perfin has been identified as belonging to this firm. I do not have an illustration of the perfin but it is referenced in Tomkins as:
See the Philatelic Links and References page for more information on Perfins.