The one I've bought is about 12" long, solid bakelite with tube over 1" thick - a real monster.

Is used to play in a jug band (The Egbert Sousé All Stars) in London in the late 60s/early 70s, and we used to be joined, from time to time by a swanee whistle player called Wink (surname escapes me) who played it like a jazz instrument and was a superb performer on it. As you say, not at all easy to play well - but I'm going to have a go (perhaps on the top of the Sussex Downs, where there's only sheep and cattle to be frightened...).