I have a smaller metal workbench in my shop that gets moved from place to place so it is usually uneven somewhere. I got an axle shim for a truck and keep it on a cross brace for need., Quick and easy. Lot of time a frame and axle shop will give you one. Just stick it under an unlevel leg and good to go.
Very timely - I have to straighten one of these on a No 6 I'm about to work on - thanks! Curious - how do you find all your tools? Ebay, flea markets, antique shops?