Sat 1-B

Realspace Models sells a resin version for about 100 dollars, it's 1/144 scale. I remember revell built one, but I'm not sure what scale it was in. Try e-bay for that one. Good luck . Steve

realspacemodels.com

Airfix made a 1B in 1/144 back in the early 70's. From what I understand, it was reissued some time in the 90's. It will be difficult to find, but seems to pop up on EvilBay every now and then.

If you could find one, the best Saturn !B is the old Estes flying model in 1/100 scale. Easy to paint as it is broken down for that. Another great flying model is from Apogee in large 1/70 scale,  kind of expensive, but highly detailed and accurate. Don't forget the 1/200 scale one in the AMT kit. In 1/144 scale, the Real Space kit is much better than the Airfix.