Mike,
Since your drive is gravel like mine, do you have a problem with the blade gouging into the gravel and rolling it off the drive with the snow? I do, especially when the ground is not frozen. My skid shoes on the blade look just like yours, and the sink into the soft drive and are worthless. I came up with an idea for a long skid but don't have a welder yet to make it. By the looks of your blade, my idea would work on yours too.
I plan to get a length of 3" schedule 40 steel pipe and weld a couple 10" long rods to the ends. The rods would be the same diameter as the skid shoe bracket holes on the back of the blade (1" ?). They would be welded perpendicular to the pipe. It would look something like this l==============l The pipe would probably need to have caps welded on first and then weld the rods to them. The finished skid would be the same length as the distance between the skid shoe bracket holes. Drill a couple pin holes at the top ends of the rods, and use washers or nipples as spacers just like the shoes use. You could add or remove the skid in seconds. By curling the blade back, the pipe would drag on the gravel (skid over it) instead of the cutting edge. Dump the blade slightly forward to raise the skid and use the cutting edge when needed.
I'd love to make one for my blade some day. I tried to get a local welding shop to build it, but they were too busy to take my order. Please let me know if you decide to build it, and if it works. Or maybe you don't have the same issue with the loose gravel like I do.