Hi bridge boy.
We had a new 504 on the farm. Great all around tractor for chores, haying, light tillage. This is a gas model I imagine , not the most economical gas tractor but reliable easy to operate.
I wonder about price with a loader and snow blower, sounds low. what kind of shape is it in? it's either rough or it's a steal. Figure the loader is worth 2000 to 4000 if it were replaced and the snowblower is worth 2000 to 4000 depending on condition, so it could be a real steal if it's all in good shape. Check the value on Kelly Blue Book.
I'd go to a IH dealer and see if you can get a mechanic to go look at it with you.
One thing to always lookat with older IH tractors is the TA or Torque Amplifier. They are a planetary gear reduction unit that gives you double the speed selections. They can go bad and with a rear mount blower you'll need to go as slow as you can in reverse. The other thing is 504s had live PTO so when you push in the clutch the PTO keeps going this will be very helpful.
let us know what you do.