A short while back I wrote about a couple of blackjacks in Salisbury. Looks like there’s another one of the larger sort in the British Museum. I stumbled over the BM online catalogue entry while looking for a dissertation on blackjacks from 1823. I’ll possibly post that in the future.
The BM catalogue description says Leather blackjack; plain except for incised crown and monogram with the monogram given as CR 1646.
External dimensions of the jack are given as height: 540mm, diameter: 275mm, I calculate that as a massive 32L or 7 UK gallons.
There was obviously some sort of mass-production of Charles I memorabilia just before or following his surrender to the Scots and the proposed invasion of England.