I did not know this. I just thought sheep was thin, weak, and flimsy. I hope to one day own a Lewis. Seems to be a Rock n Roll and motorcycle icon. I always thought the veg tanned cow was the most desired hide they had to offer.
Thanks for the great review. I really hope to see more LL's pop up here, new and old (especially patched up ones). Hope to see more pics of your jacket as it ages.
Nope. Sheepskin is a tough hide and was used a lot in British MC gear manufacturing, primarily due to availability of the animal but also because it is a good leather. I'm sure @Edward can say more about it but many 50's to 60's British motorcycle jackets were made in sheepskin which is responsible for that unique fade they got going on. You can't get sheep leather won't ever stiffen the way cowhide will when tanned at higher temperatures thus it can't be utilized for some of the products like belts, etc., as it will always remain soft.
It also tends to... Hard for me to find a word but it'll sorta turn to dust once completely dried out and the garment will get worn through, rather than crack open and flake away like cowhide and horsehide. It's another myth that cowhide / horsehide is more durable but in reality, all these jackets will last you about the same.
Lambskin is of course the same, only much thinner and weaker but I think crappy mall clothes industry is to be blamed for that as well as they shave the hide to insane thinness, thus everyone thinks lamb has no use in a serious leather jacket which just can't be the case.