An immediate pre 2nd war/start of war Armourers instructional loose leaf booklet at the Small Arms School says that these 2-piece scabbards are a re-introduced and acceptable wartime expedient, used to make use of otherwise valuable resources and should be......... blah blah blah as on these things seem to go on and on
I can only presume that 'wartime expedient' means the LAST (1st) war expedient that allowed the scabbard contractors to use up the narrower left-over slices of leather to make the scabbard out of two narrow pieces instead of one wide piece. That would make sense of course, but the labour cost in 2 lots of stitching would surely outweigh that - no? Additionally, if they were a wartime relaxation, why were they still making them into the 20's. Perhaps the relaxation in standards order wasn't rescinded so production carries on