The electrical tape suggestion that was mentioned is a highly recommended i dea when cutting new threads. I've successfully used a PARK crank remo ver to cut threads, but always use tape to reinforce the somewhat fragile p lastic barrel prior to cutting. Probably not a bad idea to leave the tap e in place once the threads are cut to provide continued support (as long a s it is thin enough as to not restrict the handle).
I always use super glue/epoxy to provide extra "hold" for the plas tic plunger mount before "re-peening" it on the aluminum shaft (clean both interior of shaft and plastic insert thoroughly with acetone prior to gluing). Simply use a finishing nail and hammer to "re-peen", lightly s triking with a hammer. Never had one fail to date (knock on wood!).
Never tried the bottom end approach, but may give it a go in the future. Sounds like it may be more work trying to get the base plug out, but like the idea of using the original threads.
I asked this same question, and owe special thanks to Peter Weigle for educ ating me on how to properly do it without buying a tap.