FYI Steve, the WW No. 8 will sew without the glass presser foot insert. I bought my No. 8 from my OSMG. He did give her an oiling and did a stitch test. When I told him later that I found one glass foot in the drawer (the Plain Glass Presser foot), he was surprised. He did not know about the glass feet. Goes to show you that OSMgs don't know everything. Charlee bought a set of glass feet from Mike Anderson of Wolfgangs Collectables. I am also searching for the glass feet to complete the set. You can see pics of my No. 8 here.
http://www.quiltingboard.com/vintage-antique-machine-enthusiasts-f22/wheeler-wilsons-no-8-a-t190935.html