Why Not Just Re-translate?

I've been asked a number of times since starting this work why I don't just do a fresh translation. The answer is multi-faceted:

1) I think the Ugai translation deserves to be preserved, but preserving it in its current state will leave it increasingly inaccessible to future readers. Yes, besides being dated, it does have some errors, but so would a fresh translation. By careful comparison of the translation with the original, perhaps my edit of Ugai's translation can be more error free than either of us could have done alone.

2) Ordinarily a translator translates into his strongest language. That would be English in my case. I thought by updating a work written by a native speaker of Japanese, I could rely on his overall use of language. This, it turns out, is more difficult than I imagined. Due to the errors I'm finding, I do end up creating sentences from scratch. Still, most sentences in the book will be grammatically what Ugai wrote, with words and characters updated as needed.

By the way, there is a very good, modern translation of Arrowsmith (Trans. Tadashi Uchino, People of the World Library, Shogakkan, 1997.) which doesn't appear to rely upon Ugai at all. The primary problem with this work is that it's a severe abridgment and simplification. Had that translator and publisher provided the entire work in Japanese, the impetus to do what I'm doing would be much less.