This underprint is believed to belong to the firm Henry Rossell and Co. an Engineering firm trading from:
1873. Unofficial underprint type 48 (over the gum) in black.
PP167 1/2d rose-red (SG 48 or G4)
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.