Hi Jim,
I believe that the hull were made in halves and glassed together. I think that is what Bud told me many years ago during a W43 survey. Anyway the hull of both the W43 and W42 are built really tough.
As to the ballast, I can not honestly remember.
Rob Sutton is building a W42 from a bare hull. In doing so, he has a vast knowledge on the W42 hulls, etc. His design, workmanship, etc. is awesome, very nice !! he has a very nice web site. Google building a Westsail 42...
I am also totally refitting a W42. A few projects lead to more projects, problems found,etc. ,etc.
One thing to look at closely, is the fuel and water tanks !! Unfortunately, the main fuel and water tanks on our boat were sitting right on the upper bilge. Not elevated in any way which lead to significant holes in both. So again look at them closely and see too if they have inspection ports, etc. Taking out fuel and water tanks and install is a HUGE project !!
I re designed the area holding the tanks. Took everything down to a bare hull and glassed in new stringers and bulkheads. Also, incorporating a bay for L16 batteries since batteries were scattered all over our boat. New tanks will be able to go through the companionway, etc. Anyway, I have documented all my work with photos and hopefully someday will create a website with the refit process, etc.
Take good look at the wiring too.
These old boats are built like a tank. See what systems have been updates since first launching.
Best of luck.
Regards,
George
W42 s/v Cadence