Andrew, the only prototype pictures I have are in the magazine articles from which the information was taken, and I don't, as yet, have a scanner. I did take a good look at my Bachmann Ten-Wheelers, and I see no problem with removing the existing valve gear. My plan is to modernize the locos by modifying the steam chest to ressemble a piston valve type. I've already completed one and when I get around to it, I'll try to get some photos to show how it's done.
The info on the valve gear comes from an excellent article in the May 1984 issue of Trains magazine, which gives diagrams and explanations of Stephenson, direct and indirect Walschaert, direct and indirect Baker, Southern, and Young valve gears.
Wayne