Converting the postwar pattern RAF BD into a wartime-pattern jacket requires a great amount of work. Offhand, I can think of the following challenges that would need to be addressed:
- wartime jackets are made in two pieces -- left and right -- which are joined at the central rear seam. Postwar jackets are made in three pieces -- back, left front and right front. The pieces are joined with under-arm seams.
- the collar would need to be replaced with a wartime closed-lapel version. Reasonably straight forward if you have adequate spare fabric.
- the wrist cuffs would need to be converted to the buttoning type -- again requiring spare fabric
- the waist band would need to be replaced to afford the longer tongue of the wartime standard. You could probably get by just replacing the belt-side (wearers left).
- there is a notch on the button side of the front opening. Not sure how this would be removed/filled. Something would definitely need to be done as this area is where the two upper front buttons are attached.
- remove the lining, as desired.
- fabricate new upper pocket flaps to triple-scalloped style.
- add additional front buttons to central opening.
- add roller buckle to wearers right