Sawyers are best known for their viewmaster 3D viewing system, where stereo images are arranged on a wheel. To complement this range, they commisioned or rebadged a number of cameras (including the Ace Ajoy renamed the Nomad). Most of these cameras were of course 35mm stereo, and are highly collectable. However their most noteworthy 127 offering was a regular (though rather nice) TLR – the Sawyers Mark IV.
The designation Mark 4 is a bit strange, as there was never a 1, 2 or 3. I can only imagine that the 4 refers to the 4×4 format, and the Mark bit was put in to give a Japanese camera that Mark Twain/Tom Sawyers link to America culture.
The image and manual were submitted by Dave Schneller who inherited his Mark IV (S#274930) from his father. The following is quoted from http://medfmt.8k.com/mf/sawyer_mark_IV.html by Karl Bryan
The Sawyer’s Mark IV twin lens reflex cameras are a rebadged Primo Jr. Type 1. Manufactured by Tokyo Optical Co. and imported by the Beaverton, OR GAF Co. (makers of the Viewmaster). The Sawyer’s Mark IV Type I was in production from 1958-1959. This camera is a 4×4 format utilizing 127 film. Note that the proper lens cap acts as a shutter release lock.
Shutter is a Seikosha MXL, B, and 1-500 speed with M, F, X flash synch. The camera shutter has markings for EVS (Exposure Value System, also known as the Light Value System). The EVS is a cross coupled system between shutter speed and aperture with EVS values from 3-18. The aperture and shutter settings are viewable from the small window above the viewing lens.
The lens is a Topcor 60, f2.8 multicoated, four element, 3 group, tessar design. F stops are from 3.5f to 22f, film wind is by crank with automatic setting of the shutter. Filters are the typical Bay 1 type.
Film setting is by the red window to frame 1, and then it is automatically indexed. When first installing film, wind the crank until the number 1 appears in the red window in the back of the camera, depress the button above the wind crank and slide the button next to is towards the back of the camera. This set the frame counter to 1, then film indexing automatically occurs every time the film crank is wound.
Focus is by knob with an ASA reminder dial in its end. Above the focus knob is a Depth of Field scale. The film chamber is baffled for flare control.
The ground glass has a fresnel lens with center focus spot and cross hair etched lines for aid in composition.
Finally for your 127 using enjoyment: The Sawyers Mk IV manual.
via 127:Sawyers.
TLRgraphy 
Bought my Sawyer’s Mark IV in fall 1958 at a Sears-Roebuck store in York, Pennsylvania. Used the heck out of it through high school and college and still have it. Very sharp lens and only a small, light handful so easy to use. Too bad 127 film is now so hard to find.
I’ve used Yashica 4×4’s, Baby Rollei’s and the Sawyers Mark 4 tlr. I’ve also used and own a Rolleiflex and a Rolleicord. While the full sized Rolleis take great pictures, for me they are just to darmed big a camera for me to carry around. The Mark 4 is the best 4×4 by a long shot. The crank is great, the viewing screen is bright, and the close focus is amazing. The Mark 4 is light and small enough to make traveling with it a breeze.