A rather well worn livery button on eBay caught my eye, particularly because it had an escutcheon of pretence in addition to impaling the Arms of the wife. I believe it to be the button of Sir Edmund Lacon, the first baronet. Born in 1750, in 1779 he married Eliza Knowles, daughter and co-heir of the Rev Thomas Knowles DD. They had one son Edmund. Eliza died in 1782. In 1783 Edmund married Sarah daughter of John Mortlock. Edmund Lacon was created a baronet in 1818 and died in 1820.
From the above my best guess at the blazon for the button is:
Arms: Quarterly 1st & 4th Quarterly per fess indented erminois and Azure in the second quarter a wolf’s head erased Or (for Lacon) 2nd & 3rd Azure a cross patonce Or (for Ward) an escutcheon of pretence Azure crusily of crosslets a cross moline voided Or (for Knowles)
Ermine a fret Azure on a chief engrailed Gules three fleurs de lys Or (for Mortlock)
Crest: A mount Vert thereon a falcon proper beaked and belled Or charged on the breast with a cross flory and gorged with a collar Gules.
Motto: Probitas verus honos (Integrity is true honour).
Image courtesy of the vendor, the-recycler33