I must take back my claim that the mystery plane is 42-98019. There is a photo of this plane after it crashed in Belgium (not Holland) on 24 Dec 44 here.
http://www.487thbg.org/Photos/MutzieB.shtml
Although the MACR says the plane flew in the 839th, the picture shows it is painted in the 838th code. It is interesting to note that the plane landed on its own and did not burn even though an engine had exploded and the wing was on fire when the crew bailed out near Ostend.
I still think the code on the mystery plane R5.