Nope. I have those on all three tractors. The 432 Comercial is missing the rear snow dozer blade mounting brackets. I would love to buy some but will make them if I must. It would be much easier to make if I can see what Gravely figured they ought to look like.
These are on ebay from time to time. I can tell you that they clamp around the axle weldments, horizontally, using long hex bolts. Here is a glimpse, but I'll bet someone else comes along with a better picture.
After seeing another thread about too low lift height, I left these brackets a bit long. this lowers the back of the bracket and should marginally raise the lift height. we'll see. putting air in the tires should help in my case too.