The Schroeckenfux company (FUX) from Austria offers a couple options for attaching a scythe blade to a wooden snath without the use of a ring clamp.
Pictured are two of the blades that work with this attachment. The vertical and diagonal slits allow for "infinite" adjustments to the hafting angle.
FUX also offers this "mounting set for patent scythe with round pivot" for use with wooden snaths. The metal plate with the multiple holes is attached to the bottom of the snath with the two screws. A hole is drilled in the snath for the the blade attachment bolt (which goes through the bigger hole on the right side of the plate as shown). The square shaped metal plate is presumably attached to the top of the snath (using the four small nails) for securing the top end of the bolt with the wing nut and lock washer. (For metal snaths, such holes can be drilled directly, and only the carriage bolt and wingnut are required.)
Special blades, with one slit in the tang and a rounded tang knob "pivot", are required for this type of attachment. The tang knob goes into one of the holes on the left side of the bottom plate, and the carriage bolt goes through the vertical slit and holds the blade against the snath. The choice of one of the five holes for the tang knob determines the hafting angle. The hafting angle adjustment is limited to these five possible positions.
To my knowledge, these blades and attachments are currently not available in North America.
(Source: Franz de Paul Schröckenfux Ges.m.b.H. Rossleithen Austria, http://www.schroeckenfux.at/index.php/en/home1
http://www.schroeckenfux.at/index.php/en/scythe-models
http://www.schroeckenfux.at/index.php/en/scytheequipment)
