The locomotive Mr. Red linked to, is a Pennsylvania Railroad Class T1. 50 of them were built in 1945-46. There are none remaining, but a replica is under construction - attempting to copy the success of the LNER Tornado. I wouldn't call the streamline design of the T1 exactly ugly. It's a nice attempt, but it doesn't quite work.

It certainly isn't as pleasing to the eye as the streamline version of the New York Central Hudson (no examples in existence - all were scrapped), or the very modest but tasteful streamlining of the Southern Pacific 4449.

Of locomotives still in existence, I think I'm most in love with the Norfolk & Western Class J, No. 611, that I saw at the Southern Railway shops in Spencer, North Carolina.

I think I remember seeing the Mallard when Bill Sables took me to the railway museum in York in 2002, but my memory is a bit foggy on that. It certainly is a beautiful locomotive.