If you ever get a chance to see Patrick McGlinchey's (Backwoods Survival) kit, and if you have any skills at all, you will be entranced. His workmanship is not just really, really, good, but his clothing is fit for purpose too. None of this 'has to be crude, it's the neolithic' rot. It's beautifully made, and from what we know of the suriving pieces, it's right.
I'm going to watch the video, but I have to say that trousers are a cloth thing, not skins. Inuit made short breeches, but everyone else seems to start with a belt and hang leggings on that, and uses a 'breech clout.'
M