From the comments, FumbleFingers says:
This coat buttons down [at] the front (as opposed to passive ...is buttoned down...) is the same kind of "inverted" verb usage as, say, This wine is drinking well, where the subject uses a verb "actively" instead of passively. It won't work in all contexts, and not all native speakers will agree on exactly when it does or doesn't work, but I personally have no problem with the cited usage.
I agree with this. "The way a piece of clothing is fastened" can be described in the active voice, even when this might not make logical sense:
A coat that buttoned down the sides
A dress which zips up the back
Shoes that Velcro shut
This usage of the active voice is especially common when describing the location (and direction) of the fastening mechanism ("down the sides," "up the back").
"Tall and well made," however, is not correct.
First of all, "well-made" is a compound adjective and must be hyphenated. But more importantly, "Tall and well-made" describes "the men"—and this does not make sense.
We do not describe humans as being "made" (except in a specific non-gradable context meaning "a member of the Mafia"). In the context of religion it is common to talk about some "Creator" which created humanity, and perhaps even individual humans, but we use the word "created" and not "made." "Made" is reserved only for deliberately constructed things.
Somewhat confusingly, we do use the adjectives "built"1 and "well-built"2 to describe a person.
So if the sentence means that the men were both tall and athletic-looking:
Tall and well-built, the men dressed in dark silk coats...
But if instead the coats are tall (long) and well-constructed:
The men dressed in tall well-made dark silk coats...
Or if the men are tall and the coats are well-constructed:
The tall men dressed in well-made dark silk coats...
Note that if there is only one adjective describing the men, it must come after the article. "Tall, the men dressed in..." would be incorrect.
1Wiktionary: (informal) well-built, muscular or toned.
2Wiktionary: Muscular and lean, having a body resembling that of an athlete.