With three suitcase weights on the front your tractor should balance a 430 pound 48" rotary mower o.k. My Bolens G174 is about the same size, and I'm basing my opinion on that. In 2WD the Bolens can't always pull the mower around corners, though. I usually work in 4WD on the turf tires. Most grass and weed cutting isn't all that demanding of engine power. If you can find a 42" rotary mower, it would likely be a good fit, but they're pretty scarce.
BTW: You'll certainly need an over-running ratchet gear attachment to go between your PTO outlet and the PTO shaft on the mower. Without the over-runing clutch the rotary mower blades become a flywheel directly connected to the tractor's rear wheels: they stop when the blades stop. This produces a terrifying surge of adrenaline the first time it happens. Note: just because a finish mower will stop without an overrunning clutch does not mean a rotary mower will behave. They're different.
Hope this helps,
Rod