I guess every tool has its day. I've had a Stanley 90J almost from the get go. I can not remember ever using it until today and the evidence of the iron's lack of sharpening would tend to prove the case. Anyway I was fitting a bottom in a drawer and in my haste to finish the drawer I didn't check the groove/ back fit before glue up. The drawer back intruded into the bottom groove by a silly mm or so, so of course the bottom would not fit in the groove. What to do, what to do. I could chisel the back flush with the groove close to the groove but I still had the full length of the back that was too high. Then I remembered I had a bullnose plane hidden some where in the tool chest. Once found I spent about 15 minutes sharpening the iron, chiseled out the high area near the grooves and used the 90J to take care of the middle area. Ended up looking OK, as if I didn't have my head up and locked during the fitting and glue up.
As always it is better to be lucky than good.
ken