byf 44 = Made by Mauser in 1944
9112S = Serial number
(Eagle)Waa/135 = German Army acceptance mark for the district of the Mauser plant
(Eagle)(Swastika) = Proof mark
Color of the grips doesn't mean much, just what plastic they had available at the time to make them out of.
Doesn't look like the right holster to me, most German leather was black or very dark brown and had hard shell flaps, but I am not expert.
Cost in 1940 was 5.60 Reichmarks, value today is a few hundred dollars. Check Gunsamerica.com or AuctionArms.com for sale prices and bids.