I've got a 1951 77 Oliver with a wide front end which uses a Saginaw steering gear box. On the front of the gear box, there is a four bolt cap with an adjustment plug and jam nut to tighten the slack on the thrust bearings in the rack assembly. At some point in the past, someone put the adjustment plug in and cross threaded it so badly that no amount of  heating will loosen it to the point that I can get it out. Does anybody have any idea where I can find a replacement cap and adjustment plug? I've tried Korves, Ollie Shafer, and a couple other guys that I know have parts but to no avail. I do know where I can get a complete box but I hate to buy that and throw away a good steering gear box other than the front end cap assembly. Thanks in advance for any help on this!