A pretty common break on a bench plane is the bottom of the knob being blown out. There typically isn’t enough surface area to glue a piece back on, so here is an alternative.
· I show the repair done with a contrasting wood, but it can be matched if you’d prefer.
Cut the bad piece off, and drill it out. A 3/4″ bit usually works, but different knobs are my require a different size. you could go smaller as well.
Measure the base size.