I appreciate your kind and generous offer. Encountering a true gentleman is made more pleasurable by its increasing rarity these days.

I agree with your assessment of the fly plaid -- a step too far in simplification and economy at the expense of tradition, IMHO.

My research continues. I have found some helpful vintage photos, photos of drummers and some related texts, including some Xmarks archives of several years ago. I think I'm getting the gist of the construction and proper wear.

I don't know if I will ever have the occasion to actually wear one. I don't travel in aristocratic or diplomatic circles, and at this point, the most formal thing I own is a black argyle jacket, converted from a suit coat. It is more a matter of insatiable curiosity -- nice to know rather than a necessity.