Hi
Yes the P seems a clue - we have many examples of the Holbrook bottles with a P, also some HP bottles with a P
And we have found one Holbrook with a P and a Knot P Knot - haha
So we have HP with just a plain P, and HP with only the Knot
We have Holbrook with just a plain P, and a Holbrook with only the knot, and a Holbrook with a P and a knot.
A glass bottle maker that used the P by itself and also used the Staffordshire Knot and a combination of P and the knot.
Birmingham pre 1911 - Handsworth Parish ?
MIKE