Jim,
I am a maintenance supervisor in a steel mill. This is a problem we encounter often. Generally the answer is to wash away the pin from the ears of the clevis with a cutting torch until you are able to swing the clevis and cylinder out of the way. Then you only have the remainder of the pin to worry about. In your shop I am presuming that is not an option so I will give you another viable, more shop friendly solution.
Take your 4 or 6 inch grinder and replace the grinding wheel with a cutting wheel of the same diameter (preferably a 6") you probably will have to remove the guard. Cutting wheels are thin and you should have no problem cutting the pin off on the inside of the clevis on both sides between your bar and the clevis.
Once you have both sides cut free, remove the cylinder. Grind or cut the remaining center section of the pin close to the bar and drive through. The sections still left inside the clevis will come out the same way.
Your local hardware may have cutting wheels for your grinder or you may have to go to a store selling mainly tools.
Any welding joint will have round stock in the diameter of your pin. Just cut it to length and drill holes in the end for your cotter pins. If you are unable to find some email me and I will send you one for the cost of shipping.
If you have any questions shoot me an email.
Matt Doyle
