Thanks for the reply Scott - Compared to some of the other transoms I have seen mine was in pretty good shape at least around the engine mount area.
I am planning on going back with the 1" brass drain tubes - I just ordered a 1" flanging tool for the drain tubes so now I can cut the originals out and replace them with no problem.
I'm not real fond of the garboard type screw plugs - pain to remove and replace everytime you launch the boat.
Other than security is their any other advantage to the screw type (garboard) drain plug?
FWIW

Once I launched my SeaCraft - forgot the plugs (crowded launch in a hurry)... Parked my truck/trailer and the bilge pumps were running full blast.. Jumped in the water - put the old 1" rubber plugs in and everything was ok. I would have had to hold my breath for a while trying to screw in a garboard plug...