Just a thought I sold one just like this ever so slight difference in that the top was Silver although not marked. An antiques dealer bought it off me in Salisbury when I did a fair down there. I don't know who made it but he said he was putting on his desk in his shop and keeping it so maybe of some worth grrr I only sold it for a tenner cos I didn't know what it was. Anyway although I can't help maybe just maybe you could yell.com him in salisbury SP1 and ask if he still has it on his desk and who made it. A long shot but maybe worth it.
Margi