This underprint is from the firm Moses de Costa Andrade & Co.
They were Ostrich Feather Merchants and Manufacturers trading, in 1865 from:
61 & 62
Wood Street & 63 Milton Street
1868. Unofficial underprint type 22 (over the gum) in black.
Vertical underprint, reading upwards
PP64 1d lake-red (SG 43 or G1)