Instead of chaining up the box blade, get a Quick-Hitch. Then it's very easy to just drop any three point implement. You can often hook up without getting out of your seat. The loader is super easy to drop also.
Then you'll have freedom mowing.
To the OP, did you try wiggling the PTO lever? On mine that switch will get debris on it and not sense the OFF position. Just hold the starter switch and wiggle that lever to start it. Ditto for the treadle pedal.
Both these I fix by just blowing out that switch area.
I have a RCK54-23BX mower deck and an older Kubota gear drive bagger for sale. These have both been sitting for three years under cover. It will fit a BX24 and a B2350 for sure, probably a BX25 also. I've modified the blower to fit also. The deck has new high lift carbide blades. They both...