I missed the direct descendant part - my bad. You need to reach out the MLAGB as this group is dedicated to the the ML history of Great Britain. I've always asked these guys why there wasn't more info saved about these men over the years. Seems like a lot of trade info has been lost over the generations. Lynton McKinzie who worked in the trade and moved hear to the USA, wrote in Muzzle Blast magazine about the deplorable conditions these workers worked in as well as their wages.
I guess you know Dickson & McNaughton in Edinburgh have Henry's original ledger.
