Wedgie,
I'm not sure if you could use this as a reference based on the Mauser action itself, but if blown up large enough you may be able to scale up from there?

Type B
https://www.gunsinternational.com/guns-f...un_id=101465426

Type A
https://www.gunsinternational.com/guns-f...un_id=101479526

Mauser PreWar?
https://www.gunsinternational.com/guns-f...un_id=101477553

Also added info from Lothar-Walther Barrels
Mauser types Page 17
https://www.lothar-walther.de/media/pdf/8d/04/37/LW-brochure-19.pdf

Hopefully Lancaster or Kudae might be able to assist in this regard as to which 'profile' matches & then go from there
Fingers crossed for you matey
Certainly a worthy project!