When I sold our line of farm equipment last spring, I kept the IH560 w/ front end loader, the disc and a two bottom plow. I figured I wouldn't get anything for the small disc or plow. The disc will be handy for firebreaks and smoothing out small ruts. I've used the plow to grub out invasive brush that was creeping out of fence lines.
You have a mower, but might want to consider a sickle bar mower as well. It was nice to hang it off to the side where you didn't want to drive the tractor or couldn't drive the tractor. I would mow fire breaks with it, then use a hay rake to wind row the cut grass into the area to be burned. Sure made burning easier! If you get a sickle bar mower, I'd look for a trailer type. The one that came with my tractor bolted to the draw bar assembly and was a real pain to put on and take off.
Used grain drills can be had cheap, but usually the seed rate is guess work. You can do about as good using a broadcast spreader over lightly disked ground. Most of the old grain drills require a prepared seed bed (maybe plowed, definitely disced). A no-till grain drill is going to be expensive and you might be better off renting. I rented one from a implement dealership once to seed alfalfa and there was a flat fee + an acre charge. Not sure if a WD45 is going to pull the average equipment a dealership is likely to rent these days.
You might look to hire a neighbor to custom drill. ISU has the current rates for custom farm work. Hopefully your neighbor is nice and is willing to mess with just an acre or two.