These are ex-Finnish military issue high-rise winter trousers made out of 16 oz wool-polyamide blend (85/15 %). They were manufactured with minor changes from the 1950s to the early 1990s. Roughly the same pattern was used in summer trousers made out of 65/35 % wool-polyester blend in 11.5 oz. Since the trousers were made by the tens of thousands, a NOS pair will cost 5 € (~ $5) in the official Finnish Defence Forces surplus store (that doesn't do online sales).