Almost anyone who has studied woodworking may remember a lesson where the instructor explained how to butt joint two pieces of wood - by hand. Part of the theory was holding a jointer plane perpendicular to the face of the wood, and planing exactly and consistently to get a good, square, clean joint. The technique requires guiding the plane with steady, unwavering downward pressure and guiding the plane with your hand on the face of the wood to keep the angle perfect. It's hard to do and requires considerable skill and practice. However, there exists a really simple solution that takes most of the skill out of the problem. Use a guide. A shooting board works pretty well for short pieces of wood but a guide attached to the plane is the only real solution for long boards. In the days of wooden planes all you had to do was screw a board to the side of your plane but with a Stanley iron body plane that's hard to do. The Stanley no. 386 Jointer Gauge to the rescue. It's easily adjusts to be slipped on in seconds to any Stanley style plane sizes 5 to 8 and it clamps rock solid. Also, it conveniently allows you to set an angle and plane to a consistent bevel. All you have to do is press the guide against the face of the board. It works. It works very, very, well. Other manufacturers made similar attachments but Stanley's was the best. Sadly, it went out of production in 1947.
Stanley no. 386 Jointer Gauge clamped to Stanley Bedrock 606
Nickel plated iron, Rosewood knob.