Rather than rebut the comments made by your "expert costumer" paragraph by paragraph, I will merely point out that this is a forum about kilts-- and as such I really don't give two buttons for his/her opinions on the construction of 18th century breeches versus those made in the 19th or 20th centuries, as muddled as those opinions are. Suffice it to say that broadly speaking I think your expert is wrong, and protests far too much to present a convincing case.

As to the value assigned to the breeches, I am of the opinion that even with substantial, and I mean substantial, not hearsay provenance, the ebay asking price of GBP2,900 seems absurd, even if your expert costumer thinks it is a snip. You maintain that these breeches were the property of Thomas Graham, later raised to the peerage as the first (and I believe only) Baron Lynedoch. Perhaps if these were the breeches he wore at some famous battle they might have some greater value. But the fact remains that they are a pair of breeches of they type commonly worn by literally thousands of people, and -- aside from your assertions -- with little or nothing to connect them to a gentleman who was, after all, only a minor Scottish nobleman and a decorated soldier. I'm sorry, but I just don't see how that turns a GBP100 pair of breeches into a GBP2,900 pair of breeches. To put it into perspective, 3,000 quid is about what you'd expect to pay for Lynedoch's sword, not his breeches.