Greg, I just took mine off a few weeks ago and one off of a truck thats sat for 40 years. Loosen it up with some penetrating oil and use a long screw driver. I wedged the driver between the tube and the block and it aligned pretty good. There's not much handle to grab, but it can be done. I would think if you get it off you could match the screw at any supply store. Let's see what anyone else has to say.
