Thanks for posting these pics. I am very skeptical of this item. In my opinion this is not a period original piece. The knife itself is original but the resin scales and copper rivets/bolsters are not period. Rather replacements at some point probably post war. The double set of rivets to the reverse lower body is also not seen on original period knives and unsure why it would be necessary here. There is no documentation for this type of resin material being used for the FKM. Even the latest knives with carbon steel blades and fittings used wooden "grip" scales. The earliest pieces used walnut scales while later examples were fitted with softer wood grips. The presence of copper rivets and lanyard bolster has long been associated with reproduction or otherwise altered FKM.
In regard to mdarnell19's question. The knife shown in the OP is a Type 1, manufactured prior to 1942 and is constructed of all plated or rostfrei metal parts. The Type 2 or "takedown" knives like the example shown in the WRF link were introduced in 1943. Both were made by SMF. As always, my thoughts only .....