Here's a thought I've long been fascinated by the idea of one countries aircraft, tanks etc being captured and then used either against their former owners or put in markings of the capturing country and test flown. German Fw190D with Russian stars Ki44 Shoki's with Stars& Bars on them, the possibilities are quite fascinating. Still working out whether we should go with actual photo's of aircraft or at least documented proof of the color schemes or let our imaginations run wild. What does everyone think? Is it an idea for a campaign? And also do we allow armored vehicles? I've seen several captured armored cars in front of German and British aircraft in the western desert and I'm sure that something similar could be said for the Eastern front. let me know what you think.

Personally, I think it a fine idea. However, if it came to be, I also feel it would likely start a long way from today. There are an awesome number of fantastic campaigns already underway, with many more to start already on the books.
That is Tomcats field of play, though.

There's a site-wide campaign recruiting for a June start called Waste not want not, Unter falscher Flagge II being organised by an Armorama member that exactly fulfills your criteria.

Hmmmm well given that the idea has already been mooted and that it's already an approved campaign I guess that this idea has already had it's day. Ah well perhaps another idea will present itself in due course.