It probably leaned against a wall for a few decades. Steam or just heat should work. Heat the wood, clamp it down straight or slightly the other way for a few days.
Collectors item. I would concur that it looks 50's or 60's but I'm not 100%. Just going by the handle stamping. I have a new old Witherell and a couple other new old axes that I go back and forth whether to use or not. So far they are unmarred. I only paid 1/3 the cost of a Gransfors Bruks so it isn't the investment. I think potentially they may be worth more in the future, plus I have a lot of other axes. If you find the right collector, you may be able to get a good trade for a few good used axes. Once you use it, it's a used axe. Instant devaluation.