(One correction to my original post, the co-ordinates 50°28'42"N 008°38'26"E are for the field at Kirch-Gons not Ettinghausen.)
Let us look at the Air Force Chronology for the attacks on 24 December, 1944, the link is here:
http://paul.rutgers.edu/~mcgrew/wwii...ml/Dec.44.html
In particular the set of targets listed in item 2 of mission 760:
2. 542 B-17s are dispatched to hit the
Merzhausen air depot (198) and
airfields at
Giessen (74),
Kirchgons (54),
Nidda (53) and
Ettinghausen (43);
secondary targets hit are
Koblenz (42), Darmstadt (7), Kaiserslautern (5) and
Babenhausen (4).
From the list on page 7 of this link:
http://24december1944.com/wp-content/uploads/FO587.pdf
We get
GU 4048 – 5034-0853 (50 34N, 8 53E is near
Ettinghausen)
https://www.google.com/maps/place/50...67!4d8.8833333
GU 3963 – 5028-0838 (50 28N, 8 38E is near
Kirch-Gons)
https://www.google.com/maps/place/50...67!4d8.6333333
GU 4393 – 5026-0859 (50 26N, 8 59E is near
Nidda)
https://www.google.com/maps/place/50...33!4d8.9833333
GU 4329 – 5020-0829 (50 20N, 8 29E is near
Merzhausen)
https://www.google.com/maps/place/50...33!4d8.4833333
GU 4098 – 5036-0843 (50 36N, 8 43E is near
Giessen)
https://www.google.com/maps/place/50....6!4d8.7166667
GU 2973 – 5053-0802 (50 53N, 8 02E is near/in Siegen which is not a target listed in the chronology)
GH 5548 – 5019-0736 (50 19N, 7 36E is just south of
Koblenz)
https://www.google.com/maps/place/50....3166667!4d7.6
Except for Siegen (which may have been a target or possible secondary that was not hit that day) the rest of the GU and GH target codes and locations seem to match up quite well with targets that were actually hit. In particular, it seems to suggest to me that
GU-4048, (at least on that day and for that attack), was Ettinghausen.
Just to add to the confusion, there is a very long report here:
http://401bg.org/Archive/Document/Mi...Report/118.pdf
which contains a lot of information about an attack on the I.G. Farben synthetic oil refinery at Merseburg on July 29, 1944.
On page 34 the target code for the factory is given as
GU-4048.