>>2474909A small French surplus store. You can get 'em in you look around though, they're Swedish M39 trousers. I paid about €20, and I'd easily pay twice that if I had to buy them again. There's a nice M39 jacket too.
The ankle wraps are puttees, specifically Belgian WW2-era puttees. It's important to get ones that are woven purposefully in the right dimensions, not modern repros that are cut from a big piece of wool and then stiched in the sides. Helpful to keep debris and bugs from getting into your boots or pants, can be tied a bunch of different ways depending on the desired use, a bit fiddly to don and doff, but easily worth the €10. Especially since I'm tall and pants tend to be a bit on the shorter side.