mirror cells + spiders - UK suppliers?

Does anyone know anyone based here in the UK that make good quality, fully
adjustable mirror cells and spiders? I have a c.70's 6" f/8 Hinds ("A"
grade) mirror, and a 1" elliptical flat that I want to recommission into a
Newtonian OTA. I want the tube to be open at the mirror end, and for the
mirror cell to fit inside the tube. I know about Beacon Hill, but was
wondering who else are making them, if at all. Other than that, any
recommendations for suppliers overseas?

Many thanks,
Dave Randell