I can provide a tiny tidbit of detail. I got a close look at a U-2 at the USAF Museum in Dayton, Ohio (one of my favorite stomping grounds when I was growing up in Columbus. The aircraft had just arrived, and hadn't received attention from the conservators and cleanup crew yet. Sitting on the dashboard coaming was a light-colored, varnished wood stick, about a foot long, with a wad of some cotton-like cloth on the end. My fellow-enthusiast friend and I looked at it for some time. The best explanation we could come up with was that the pilot used this gadget to wipe condensation off the windshield.
That would be a nifty little detail for a model.