Cannot comment on the alcohol, never touch it.
Let's take the detective approach.
1. It's a 5 shilling heavy lifter, almost always a Parcel Post if not a script cancel.
2. There is a rough circular impression, and its a smudgy impression.
3. Parcel hammers were rubber, and oft deteriorated.
4. Parcel hammers had a ring and sometimes a name and / or number.
That would be my best guess, albeit there are what look likes two strikes of differing cancellers.
CALLINGTON rubber hammer, BOM (you would swear the "B" is an "8"