Join Date: Dec 2004
Location: Route 66
Interesting question, and I think you have pretty much some good understanding of wat the variables are. The reality is that most scabbards were made of materials as you have noted.....wood (timber) wrapped usually with sewn leather and securing fixtures such as chape, throat and mounts for carry rings or baldric.
As may be imagined, these from such early periods seldom survived unless they were kept in static and controlled environment. One of the most commonly replaced components for swords was obviously the scabbard.
One of the only studies I am aware of on scabbards is by J.D. Aylward in "Small Sword in England" (1945) which discusses mostly these civilian swords of 17th and 18th century and does describe methods of production, types of wood and materials. It might be presumed that these processes probably did not change that much from the earlier periods you mention.
Obviously scabbards purely of leather and such flexible materials would not do well when a sharp blade was being withdrawn without some firm support.
Knives of course were of lesser expanse and length (usually) and a firm leather scabbard sufficed.
In later periods with the advent of regulation military swords, the use of formed metal scabbards was common, however it was often the case that these actually dulled the blades. In the 18th century scabbards often had wood inserts within the metal frames.
I have not been aware of museums having catalogs of either swords, scabbards or the like 'available', but some auctioneers will occasionally have lots which comprise parts etc. from various weapons. I would contact the major houses to ask if they might have such instances, and perhaps might direct to examples they have had which had the scabbard surviving with it.
Hope this might be of some help. Best of luck, and thank you for the most interesting question.