I like MacKintosh for his designs, not his concern for the working classes!
The stopper does fit, but on closer inspection it may have been reworked to fit. From what I've read from the old Whitefriar's carborundum wheel operator's recollections on the Whitefriar's website each stopper was tailor made for each decanter. I have 2 Wedgwood decanters and 1 Dartington (3 Dartington?) and the stoppers all fit perfectly - yet they are not interchageable.
Anyhow, whilst looking for numbers and giving the thing a good once over - I've noticed one of the squares has a big chip out of it. So before I worry about going any further, I need to make a note to self - check the condition properly before parting with the cash. Thankfully it was only £3.
I never really use decanters. I like to show off the spirits I offer to my guests!
I'm going to start a thread on this but for cleaning decanters - Magic balls, copper or stainless? Which is best?