I bought them from
Tre-beirdd Farm (Mold), Reclaimed Building Materials (and furniture, and ALL sorts of fascinating things). Do not go with a trailer and leave your wallet at home for the first visit or you WILL be temptedhttp://www.yell.com/b/Tre_Beirdd+Farm-Salvage+and+Reclamation-Mold-CH71HS-183503/index.html
NOT an easy place to find even with the map because the entrance off the main road initially goes into the grounds of the school next door.
I bought a couple of dozen of these things and then fitted them in place of the newels on the staircase and landing of a house I was helping refurbish. These are just the left overs.
Summer - don't see how you can have anything 18th century and Victorian! Victoria was 1837-1901