Sandy and all,

I notice in the links Eddy posted that the B-L does not have valve eccentrics out on the paddle wheel hubs.  I thought I might share some photos of the paddle wheeler Portland. It too has internal mounted valve gearing.  The eccentrics are driven by a crank arrangement  off of the pitman arm. I don't know if this will be of any help to you in your design or not.  Maybe this might not be new to you but others might find it interesting.  Check the Photo Gallery under Bill Hudson.  I believe there is a (homemade) video available some where of the Portland engines etc. running under steam.  I think I'm just going to have to bite the bullet, buy a tank of gas, and drive up there again and get more information.  

Bill