I'm near Concho, AZ, at 5600 ft. on unimproved dirt roads in area of 40 acre parcels. My neighbor and I just acquired a 1989 Kubota L2550 with FEL and a 6 foot CountyLine 3pt blade, and 5 foot CountryLine drag box for our road maintenance (about 1 mile of hilly road total). While it's no grader and reshaping the road grade substantially is difficult and slow, it does do the job. We wait for good moisture conditions; it will not readily move dry hardpacked clay. The blade is used to move material from the shoulders into the road to fill gulleys, the box is the primary road grading tool, with FEL used for pot hole filling. Either the blade at 45 degrees or the box would do your washboard if it was rain softened a bit. We plan to add 150lbs to the low side of the blade to improve cutting power. If one of us stands on it, it cuts like fiend. Both blade and box are ideal, if I could only have one the box is the hands down winner.
I had my doubts about the compact size of the L2550, but with 4WD, filled rear wheels and reasonable expectations it does the job quite well and we are very happy with our low budget DIY road grading. As it happens we've had a few inches of rain in October, something that has never happened before in the last 40 years. Our road is looking pretty damn good.
This was my initial thought as well, specifically the L2501 model with a grade box and land plane grader scraper.
Update on the domorequipment TP-84 pull behind grader scraper: the rep returned my call today and quoted me $4,300 + $700 shipping. I'm new to the whole implement world, but that was about double what I expected! It seems like getting a used tractor in the $10-15k range would make better long term sense so it could be used for other tasks as well. But then again new L2501 packages are around $19k so it's easy to creep up the cost ladder and justify something new.