Winter trousers "Pea" or "Dot", "Erbsentarn". Good camouflage pattern, heavy dense insulation, as it was in the original (not a synthetic winterizer). The size is about 48 or S, and you can wear it like 50 or M, but then you need to wear a field jacket over your pants (and not usually fill them with a winter uniform).
We have only one such pants. You can estimate the size if there are similar pants at hand or even some pants that suit you. You will need a flexible rope meter.
Pants length along the side seam — 105 cm;
the length along the inner side seam (that is, from the fork to the bottom) is 72 cm;
waist width is 51 cm (that is, pants fit on the waist 100 cm, including all the clothes that are worn on this waist).