Moreno, Teresa K - (tkmoreno)
It has been a few years since I was in the UK, but your mountmaker colleague would likely find these of use.
Preservation Equipment Ltd. http://www.preservationequipment.com/
Conservation by Design Ltd. http://www.conservation-by-design.com/home.aspx?pagename=home
4D Model Shop http://modelshop.co.uk/
The Museum Workshop http://www.themuseumworkshop.com/experience.htm
Plowden and Smith http://plowden-smith.co.uk/
This one is in the US but does ship internationally.
Benchmark Museum Service http://www.benchmarkcatalog.com/
He may also consider contacting people at West Dean College for more references. https://www.westdean.org.uk/
Teresa Moreno, M.A., M.A.
Arizona State Museum | University of Arizona
1013 E. University Blvd. | P.O. Box 210026
Tucson, Arizona 85721-0026
tel. (520) 621-6314 | fax (520) 621-2976
I work at the BM – we buy most of our standard tools at the usual places – Screwfix, Axminster etc., and get most specialist materials etc. from PEL. We also scout about for more specialist tools and get them from a range of suppliers as needed. If you want to put me in touch with the mount maker I can advise them directly if that would help?