I worked with two different patterns and two different construction guides but found little consistency. I highly recommend drafting up the pattern in a muslin before starting, as the pattern sizing does not correlate to any known size chart I could find on the internet, and you don't want to make mistakes with your nice wool fabric.
Front A/B and Front Facings H & I: The facing pieces have a notch at center front (where A & B join on the front). This is because the collar is stitched right sides together and turned, but the overlap flap (B) is stitched with the wrong sides together with the seam allowances enclosed in the binding applied later. I had trouble aligning the fabric pieces on both jackets at this point, and ended up taking pattern pieces A, B, J, and K (without seam allowances) and tracing new H, I and P pieces.
Sleeve placement: The sleeves turned out to be the most difficult part of the jacket. The designer's notes show the back sleeve seam joining the torso below the piping seam, while some authentic uniforms have the underarm sleeve seam match the torso side seam (A/D junction). I could not get the sleeves from either of my patterns to align in a way that would match either of those placements and still fit the armscye correctly. So I scoured books looking for a rule for placement, but found that the amount of sleeve cap ease and the placement of that ease varies widely by design. It is common to ease only the top of the sleeve and sew the lower portion at a 1:1 ratio with the longer vertical seam running down the back of the arm. The sleeve cap on my patterns was 16% larger than the armscye, which would require a good deal of easing. On my test jacket I tried easing across the top of sleeve piece E from side seam to side seam, but still was left with gathering wrinkles. The pattern that did have notches placed them quite low, so a full 75% of the cap would be eased if they were used as landmarks. In the end I decided to stitch a bias strip along the entire sleeve seam, then aligned the top and bottom of the sleeve and armscye, and this resulted in the piping aligning with the back arm seam.
Back pattern piece: Depending on the pattern, the center back piece might be cut on the fold or have a center seam. Movie stills seem to show a seam down the center back.
Front overlap corner: one pattern had this curved but again after viewing movie still and reading construction guides I changed this to a point.