I remember Water Rat very well, she was a sweet little 2 berth, as you say, very curvaceous. the second one of that name, the first being only the 3rd boat built I think.
I hope I've managed to attach a photo of Jemima, not sure how well it will come out as I have had to reduce the number of pixels to stay within the allowed 3mb size!
She has Leaky windows, hence the plastic covers over them. I'll try to find one without as she looks much better that way!
Another couple of photos, the first one including Silver Heron, one of the very early boats, which was built in 1954 and is miraculously still afloat, due largly to the valiant efforts of David Brown, whose family owned her from 1969.