That snowblower is an Ariens, still built in Brillion, WI.  It is exactly like my parents first one.  From the look of it, it's a late 60's-early 70's machine w/ at least a 5hp motor.  A real workhorse!  I have the 8hp version which was my Grandpa Baumann's.  He bought his in 1968, and still going strong.