Thanks, John. I did find a couple of scientific suppliers after I
asked the question, but the prices they charge are wild. For example,
a 4" OD set from Cole Parmer:
is a mere $368 + VAT!
I've found one on ebay from a US supplier of roughly the same size
that has cost me $70, including shipping. I've no idea what the
quality will be like, but at that price I'm prepared to take a
Ebay link removed. Sorry no Ebay links on Orchid
Alana, I did look at all the enamel suppliers I could find in the
UK, but all of them seem only to stock porcelain sets.