Well you could feed venison(deer meat) but I wonder why? If fed sparingly as you state, it will do no harm. But then, it will not really do much good either.
What I find of wonder is, people always want to talk about idea or perfect or best, this and that and the other thing. Then want to feed something of little value. You know, thats not idea or perfect or not even close to best, heck lies somewhere south of OK. If you want to, go for it. But please report back.
I use to feed my albigs rabbits/birds/snakes and other roadkill, but it sorta was a neutral, it didn't hurt them, but it really did not good either.
About your rudis skin, it appears to have some travel marks. But overall appears healthy. Give it normal decent husbandry and it will be fine. heck monitors are tuff as nails. And even in nature they commonly have crusty skin. They are not a snake.
Good luck