I'm not positive what exact configuration of hull-deck joint you have, but I have an Allied Seawind ketch that I did the same job with maybe 8 years ago.
Thanks for the info SoulVoyage.
Regarding the bungs, my post was a little unclear. Of course I realize that I can't save the original bungs. I was just wondering how to remove them without damaging the hole, so that when I put the new ones back in the holes still are "clean". In fact, I think I found a good solution... I used a Dremel tool with an 1/16" endmill, and carefully route out the bung. When I get close to the edge, it usually pops out. Doesn't take much time.