Courtesy of Andrew Beelen, member of the Facebook group Rhykenology, shared this interesting H. Chapin sash plane:
Listed in the Bliven & Meade catalog as a Self-Regulating Screw Arm Handled Sash Plane, it is in truth a double boxed handled sash plane, non-regulating. The heel is stamped Wm. McK. Perry
Andrew conducted some research and discovered that Wm. McK. Perry was a carpenter and builder living and working in Washington, D.C.
Once again, living proof that custom orders from wooden plane makers were common. I've added the link to the Bliven &Meade catalog after the photographs.