Since you live in the 'rust belt' it is likely it is rusted. Try soaking the entire Bowden cable in your favorite rust solvent, and wiggling it. It might be necessary to remove the whole cable assy and work it over.

The PTO most likely runs off a gear that reaches into the trans. To engage some part of the cluster or other gear. If the PTO housing is removed, trans. Oil must be drained first, or you will get an oil bath.

I think if you Google PTO's, it will be explained. PTO's are specific to each trans.

Ed

'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.