Welcome andyr! Doing this while half asleep, so bear with me. From what I have found so far.......
http://www.airgale.com.au/histories/HISTORY%20OF%20THE%20WILKINSONS%20Update-2%20%5B070222%5D.htmFrom the section WILLIAM AYSCOUGH WILKINSON 1796-
1853"Shortly after the death of her husband, Emma appears to have sold off her share of the core Wilkinson businesses at Ludgate Hill to her brother-in-law, Charles Wilkinson, who carried on the family tradition in a new establishment at 8 Bond Street and 22 Grosvenor Mews (the factory was at Little Charles St, Munster Square)."
From the section FREDERICK WILKINSON 1828 - 1877
"In 1909 the Old Bond Street building was demolished, and the company, re-named Hindley and Wilkinson, relocated to 70/71 Welbeck Street."
So I think that should give you a time line of 1853 to 1909
Looks like hosman and I are both having trouble sleeping
But it's likely a lot earlier on that side of the 'world'
Will leave the value aspect up to those with more knowledge. Pictures would really be necessary in order for them to give an estimate on $$.
