Probably 25 yrs ago I found a broken piece of road grader cutting edge in a scrap pile at Dad's. He ran the neighborhood welding shop trying to keep neighbor's old farm equip. patched up & running. Normally He didn't charge for repairs so He tended to stay busy while the welding shops in town were begging for work!
ANYHOW, this cutting edge was 40+ inches long, broke on one end where it had hit something REALLY solid, 1/2 in thick and about 6 in, tall with a real nice arc to it. I cut the broken end off square. That was before I had my bandsaw. Took THREE new good hacksaw blades to cut it off I remember! I took some 1/4" thk plate some big hardware, and other scrap I had sitting around and made a bracket to bolt the blade onto the mule drive of My 72 in place of the mower deck. It angles nicely to three different angles each way, and with the 40+ yrs of mowing duty the mule drive lets the blade tilt a bit also.
I put it on the old 70 this spring along with the tire chains on the old 6-12 GY turf tires and did almost ALL the finish grading on the landscapng project around the house. There is a limit to what You can move with a 700# tractor with a tired 8 HP engine but with enough passes I cut at least 1-1/2 ft off the bank along side of the house that was letting water sit beside the foundation and leak into the basement. There was a bunch of old roots left from bushes that had been beside the house, and the big tree in front of the house, plus a few weeds, but once I got down into clear dirt without all the trash I can make that blade cut! Nice thing about a center mounted blade is I can stand on it while the tractor is moving and really make it cut, and it really works great for leveling ground, where a frt or rear mounted blade tends to make the grade worse.
Only complaint I have is with the little 6-12 tires the blade only clears the ground by about 2 inches, it would be nice if I had another inch or so clearance when raised.