Ok I like this deck because I'm currently working on a modern scavenge deck and if you dont mind, I have a few suggestions that I thi k will make this deck more efficient and legal.
Obviously you'd have to pull
deathrite shaman as he has been banned for a while. I'm assuming you are aware of this and this is just an older deck.
I would replace him with a 4-of of tarmagofy as his power and toughness are static based on the number of card types in all graveyard and therefore, his power will be higher. I would also cut
vampire nighthawk as it doesn't really seem to fit and would open up slots to run 2 more Varoltz and that is your "star" of the show here.
Next I'd cut sisters and Jared and replace with
rotting regisaur.
Next I'd cut
deadbridge goliath and replace with
skullbriar, the walking grave.
And id also consider
deathgorge scavenger but not 100% sure of it. Over all, I think you were on a good path. Feel free to check out my version when it's done. Cheers