Jim.......what Bob sez........the "twist" in the PTO shaft is usually imperceptable and usually don't hurt 'nuttin' until it comes time to remove the $$$ hydraulic pump. Like now. New modern 1-3/8" replacement PTO shaft $150 (cheap)
Usually, you can reach it with a "saws-all" thru the removed 6"-dipstick cover plate. Don't have a saws-all? rent one. Simple, eh?
It usually gitts twisted by brushhoggin' without an over-running coupler (ORC) $65 (cheap) ........Dell