Those two kits probably are capable of being turned into decent scale models. I have to say, though, that their flat decks and that ridiculous "wood grain" on their hulls (which makes each ship look like it was hacked from a single log) rule them off the list of kits I want to build during the limited time left to me on the Orb. Fixing the planking detail (or lack thereof) on the hull would be practical; adding camber to the decks - and all the bulkheads and other parts that they cross - would be a major project.
As I've said more than once in this Forum, I generally have a pretty low opinion of Heller's sailing ship kits. These two certainly are among the better ones. I would, however, have to give higher marks to several others, the 1/100 Victory and the 1/75 Reale being rivals for the top spot (and the "Viking ship," the Syrene, and the Soleil Royal close to the bottom). If I remember correctly, the big Gorch Fock is also an extremely nice kit. To be fair, there are (or were) quite a few ships in the Heller line that I've never bought or seen up close. I've heard good things from knowledgeable people about the St. Louis, the Belle Poule, and the Chebec - among others.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.