tel
i,m intrigued ,
how did you help centre the grind?...
i kept goin from one side to the other and losing metal,...
do you scribe a line?, or use a marker pen,....?
best is to scribe a center line along the edge and a grind hight on the sides then file between the 2
i use a vernier caliper but used ot use a bit of metal half the thickness chisel ground on a flat surface or some use a drill bit the same dia as the thickness tho i find this leaves a thick line
ATB
Duncan