[Schenck]

Jan

ULTRA files are only sorted by dates, each period being stored on one microfilm, in so covering radio traffic regarding air, ground and sea situation. The only way to get necessary data on LW is to sift through the microfilm roll that covers dates you are interested in.
Messages on LW include reports about operations for a particular day, orders of battle and a lot of miscellaneous stuff like orders from/for ARCs and so on.
A daunting, but very satisfying task with lots of up and downs considering what you are after.