The surveillance mission itself was kept secret well after the War. A notable pioneering test pilot was employed, who happened to buy property on a hill above my family after he retired. He was also involved in a heated controversy and personally rivalry over who actually first broke the sound barrier. According to one definition, he (Col. Comstock) did it first during a dive six or seven years before Chuck Yaeger famously did it in free flight under a different branch of the military, with its own set of rules. Numerous books have been written about the dispute. Comstock became so bitter about not being duly honored that he eventually took a gun to his own head, but survived, making him more bitter than ever. But he was recognized and repeatedly medaled for being an "Ace" combat pilot in both WWII and the Vietnam War; he died in 2009. Yaeger himself was frequently encountered fly fishing in the high country. So much history in those mountains; all the way from Ice Age hunters to the jet age, even a crashed secret carbon fiber early Stealth plane.
One of my own family members had worked in Defense think tanks, and had in fact grown up under Nazi occupation, so the conversations got pretty interesting. I presume that certain specifics remained hush-hush due to the nature of the surveillance aircraft, or their cameras. I've seen classified sample photos from the 70's and 80's, for example, that would almost outright blow away what people would think possible even today. Of course, the cameras probably cost hundreds of thousands of dollars too, and gave much more detailed information than satellites do now. Anyone who has ever worked with even WWII style 3D stereo viewers in relation to sequential aerial photos knows how much more intuitive they are to interpret than anything Google Earth etc. I did that at one time in relation to geological and archaeological research.
Besides heroin, Hitler resorted to a lot of currency counterfeiting; he was getting desperate. Cash was needed to buy oil in particular.
Armaments sales themselves have all kinds of dirty secrets. US heavy arms manufacturers were selling Saddam Hussein's Iraq regime all kinds of things even when we were at war with Iraq - just as long as he couldn't hit our planes with them. The US would bomb what our own defense industries just sold Iraq, and then Iraq would buy more. If you've ever seen a defense industry trade magazine or international conference roster, it would make your blood curdle. It's all about the money. Apparently, the situation was analogous in WWII. The main problem with Germany's internal manufacture of things like tanks and trucks is that there was almost no standardization of spare parts between the different suppliers. That fact alone doomed the invasion of Russia.