I finally finished tuning up the 60 1/2 plane I bought back in spring. I don’t know how old it is but it was not performing upto snuff.
1) The adjustable toe had an ugly spot on the center bearing area. This caused the toe to ramp upwards as you tightened it up. This caused the exposed blade depth to change as you closed the mouth up, A real hassle if you want to go from fine shavings to something a little beefier.
Solution. Filing. Honing (with sandpaper) and being REALLY careful in general during this. Too easy to take it the other way where instead of pressing out it could sink in. Once level (after about 500 adjustment/check cycles) it was time to move on.
2) The lever cap did not have a consistent bearing area where it pressed against the blade. This means the blade is not fully supported across the width opening up the possibility of chatter.
Solution. More sandpaper honing after a Light filing to create the angle. This created a smooth flat area that presses firmly against the blade.
3) Blade not square. This is a big issue as the 60 1/2 doesn’t have a lateral adjustment which you might be able to compensate with.
Solution. Well you know this one. I personally use sandpaper and the Veritas Mk I jig. It took some time but I ground it down and honed it up. While everything was out I touched up my Craftsman No. 5 and my Ohio No 7 blades as well.
Heres a slice of Hard Maple end grain to show that everything is as it was meant to be.