Six or seven years ago I 'won' a new Stanley G12-020 block plane in a 'white elephant Christmas party.' It was inserted into the collection by a remodeling contractor friend for whom it was a duplicate. Today I decided to see if it could be easily used with a shooting board to square up and edge. I was surprised to see that the sides are out of square, approximately 91 degrees instead of 90. Since the sole is the widest part, I would need to take off about 0.012" out of 0.158 - 0.168 (it is slightly asymmetric at the throat) or about 7 to 7.5% of the stock. In the process, I also see that the sole is high at the throat and the tail end against a Starrett hardened combination square blade, and slightly convex in front of the mouth (the moving plate) and slightly concave behind the mouth. This is using the "light test." I checked with a feeler and it is no more than 0.002"
1) Will I significantly compromise the strength of the plane if I try to square the sides with the sole?
2) Will the performance improve if I grind down the sole using wet-or-dry paper on a flat stone surface using increasingly fine sheets, as though I was sharpening the blade?
3) If so, how fine a sheet is advisable?
Are these errors typical?
Thanks,
baumgrenze