L. Cornelissen & Son
105 Great Russell Street
London, WC1B 3RY
Phone 020 7636 1045
Fax 020 7636 3655
These guys are right down the street (2 blocks or so) from the British Museum. They have their own line of oil paints and a collection of gilding supplies and calligraphic pens/inks the like you don't see here in the U.S. You can download their price list etc. from their website. And yes, they fullfill orders and do a direct mail business. I bought 4 small jars of different gold paints (from pale, tinted silver to more rosy red golds) and a calligraphic ink (permanent) which hopefully will work in my fountain pen. I am loading the fountain pen with india ink--which scares me a little that I might wreck the pen...but without a little risk, forward movement is slow. They had nice sketch books and brushes. They have automatic pens, poster nibs, and the entire line of Mitchell pens that you rarely see these days.
The interior of the store was fitted out with worn black painted wood. Lots of shelves with thin drawers underneath or a solid wall of drawers (as in the wall shown above). They carry these enormous apothecary jars filled with every color of pigment imaginable at the top of all the shelves that wrap the small store. Every package is beautifully wrapped up in paper and put into a carry bag. They also have printed lists (same as the pdfs) that you can get directly from them.
The british have a ton of Pilot pens we dont get here--including a weensie fountain pen called the Pixie. Check em out.