Driveline vibration!!! I need help!

Take the drive shaft out and check the joints for any binding, then take it to another machine shop, and have them spin it up,, that vibration that comes and goes at 50-60 mph is classic u-joint symptom,, but if shaft was accidentally contacted by hoist, (I've done it), could be bent,.. but it sure has driveshaft symptoms, and machine shops make errors too,, believe me,, they dooo...