The 1920-style uniforms worn by the Nats on Saturday night were, to be blunt, done with a blind eye to accuracy. The "W" logo on the sleeves and caps were cartoonishly big. In 1920, the "W" was relatively tiny on the cap, and only slightly bigger on the jersey. Of course, they didn't wear numbers then, either, but fans are so conditioned to numbers identifying the players, leaving them off was never a consideration.
A few years ago the Orioles played a throwback game against the Cardinals in St. Louis during interleague play, and wore St. Louis Browns' uniforms, the only nod they've given their heritage since the franchise moved in 1954. The "Browns" uniforms they wore were unlike any the real Brownies ever wore. You can't blame the Orioles - the unis were arranged by the Cardinals as the home team. It's just unfortunate that the moguls at MLB think they need to tweak the old time styles for the modern audience.
Isn't the whole idea of wearing throwback uniforms to give the fans a taste of what the game was like years ago? In that sense, I'd almost rather see them use flannel as the dominant fabric for throwbacks, but I'm sure the Player's Association would have issues with that. Ironically, the last generation of flannel, worn in the early 1970's, is actually lighter and more breathable than the synthetic fabrics used today.
The Nats and Orioles play a throwback game at Camden Yards on June 26, wearing 1970-style uniforms, the Nats in the livery of the expansion Senators. I've seen those shirts, and they're pretty close to the originals. The only perceptible difference is the size of the lettering: the throwback shirts feature "Senators" slightly larger than it was 40 years ago.
The numbers are also larger; the expansion Senators, for reasons known only to late equipment manager Fred Baxter, wore seven inch numerals, when the industry standard was eight. Before the era of player's names on jersey backs, numbers were attached five-and-a-half inches below the collar top. In recent years, those numbers - on the reverse of the few clubs that don't wear names on the back - have moved down another inch-and-a-half. Not a big deal, really; just an observation.
Throwback uniforms and caps are also designed to sell licensed merchandise, and really, economics are what it's all about. A little more attention to detail would be nice, though.