Totally understand. Hold on to that scabbard - you never know when you might get a Lend-Lease M1917 that needs it!
To throw a wrench in the works, the first pattern M1917 scabbard was short lived - I believe the design was dropped in October 1917 so........the best bayonet for that scabbard would be a P1913 US surcharge or a hybrid P1913/M1917 or a M1917 without the clearing hole.