I bought one similar to yours last year. It doesn't have the snow blade or chains for the wheels but it does have a rotary mower on the front of it.
Mine is from about 1965, I can't remember the exact manufacturing date right now, but it was when Gravely was owned by Studebaker. It's called a Model L6.
The previous owner had just spent $200.00 to have the magneto overhauled. I paid $500.00 for it. That was probably too much, but I sort of owed the previous owner a favor.
Tom in TN