Just as an update having seen some different makes, it appears some are
made out of copper clad Kapton, which is a thin flexible plastic sheet,
suitable for high temperatures, made by DuPont. The copper cladding is
etched into the element - rather like a PCB - and then laminated with a
second layer of plain Kapton. This sounds like it would be suitable for a
small production run - I know of several others who'd like replacement
elements. I've found a couple of suppliers of this stuff in the UK but not
had any replies to my e-mails.

Anyone have details of this process and suggestions for a supplier?

--
*When the going gets tough, the tough take a coffee break *

Dave Plowman London SW
To e-mail, change noise into sound.