Steve,
* Does your byf '42 have a lower case alpha suffix letter under the "3744" marked on the vertical face of the frame just forward of the trigger guard?
* ALso, can you tell us what the magazine(s) S/N's are including the suffix and waffen Inspector's number?
* IIRC, about 113,000 byf '42's were made over the 10 months Mauser remained in Luger production that year before switching to essentially Army P.38 production.
* Maker, City, Date, & Army Inspector's acceptance on the holster are evident & pretty self explanitory. If the right belt loop requires repair,
lugerholsterrepair@yahoo.com (Jerry Burney) is as best as they come for a period correct repair.
* Nice find & the lineage to you from the original US soldier is just part of the history of this rig attesting to the value these former Luger's owners felt for this example. Three mag suggests it shot pretty good too. One mag was probably used to conserve the other two original ones from breakage/wear/etc. While you may not be able to access the deceased vet's history, you may be able to explore the 268th Port Co. listed on the capture paper's for battle history dates/locations.
* Hope this helps & welcome to the Forum.
Respectfully,
Bob