Jim's right... I've got the Robart's for my Bates SBD. I think they're the same gear design, mine are just smaller (1/5.5 scale). They're really nice and quite accurate. A little pricey though, and it took a good 6 weeks to get mine. That may be because they were an oddball scale.

Here's pics and docs on the installation of mine...

http://www.renderwurx.com/rc/SBD/htm...g/retracts.htm

Neo