I recently acquired one (924026) that I'm repairing, probably to sell. As trout says, it's a serious machine.
In addition to his advice, I'll add a few suggestions.
I was getting some easy parts from my local small engine -bricks+mortar- store and mentioned that mine
didn'
t have electric start. 8HP Tecumseh. My guy says "hah, them always pull over". Well, even with stale gas I primed her and choked her and chuff, chuff she coughed. Put some fresh gas in and away she went. In my part of Ohio, snowblowers don't see a lot of use.
Check the little crankcase on the auger. Top it off with either 90 weight gear oil or 0(zero)-grease. Or maybe drain and refill it. I just rebuilt mine and used some of both.
trout's posted url will get you the manual, the exact one. (
Big Thanks to trout!! My Google-foo is rather poor)
Look for all the grease fittings and grease them. Look in the manual, and oil what needs oil. If it needs repair, it's probably going to cost a lot. I have way too much time in the one I have. Being so old, rust has just about bonded some of the parts together. I have many hours pulling the bearing that supports the second stage auger. But it runs like a watch now. Both drive belt idlers aren't lined up correctly and I need to adjust those.