Sentence:  And no use for anyone to tell Charles that this was because the Family was in mourning for Mr Granville Darracott […]: Charles might only have been second footman at Darracott Place for a couple of months when that disaster occurred, but no one could <WSD>gammon</WSD> him into thinking that my lord cared a spangle for his heir. 
Meaning of the word marked with <WSD> tags:  To deceive, to lie plausibly.