Type ? (Unlisted by S.G.)

This overprint is from the firm Francis Heathcote Wenman & Co.

At the time the overprint is believed to have been in use they were operating as Ship and Insurance Brokers trading from:

    20 St. Helen’s Place
    London E.C.

The firm however had various names and locations during its lifetime:

1865–67 Francis Heathcote Wenman of 19 Bishopgate St. London E.C.
1868 Francis Heathcote Wenman of 20 St. Helen’s Place London E.C.
1869–71 Francis Heathcote Wenman & Co. of 20 St. Helen’s Place London E.C.
1872 Wenman, White & Co. of 101 Leadenhall St. London E.C.
1873 Wenman & Co. of 101 Leadenhall St. London E.C.
1876 Wenman & Co. of 3 Suffolk Lane London E.C.

This was an unofficial overprint, privately printed in black, reading upwards.

The overprint is believed to have been used from around 1868 (as the only known copy is on a 1d lake-red plate 120 which was put to press on 8th September 1868).  This also nicely ties in with the overprint and the trading name of the company at this time.

1868. Unofficial overprint type ?? (unlisted) in black.

Vertical overprint, reading upwards.

PP? (unlisted) 1d lake-red (SG43 or G1)
Plate 120