So near as I can tell, I've sort of mined as far as I can for interesting tidbits on who did what and whatever. I've long thought about the only thing left is actual translations of anything pertaining to the creation of Viper and Sogna in general (possibly Silence). Two things I've considered here:
One, what is even worth translating? Anything? There's the Sogna Information booklets, which sound like they could be interesting, but I don't know, maybe it's just some advertorial pablum. Perhaps the interviews that pop up in artbooks could be worthwhile.
Two, as far as translators go, anyone I know who I'd ask uhhh...I don't know how they'd react to the material. Maybe I'm underestimating them, but you can understand how I might not want to push it. There's mercenary translation work, but pros are sort of out of the question and I doubt the folks getting pocket change for translating manga/doujinshi lines like "iyaaa stop it" and "you're stirring me up" would be all that reliable accuracy wise unless they already really have an interest in the material.
Of course, I've only ever thought about it and never so much as suggested anything about it here, so yeah, putting it out there.