While I’m thinking of desiderata, wouldn’t it be relatively painless to produce one or two LCL-style volumes of ‘Hellenistic Jewish Texts’ in Greek and English? Just thinking off the cuff, if we included books that are a) excluded from other major corpora (LXX, Philo, Josephus); b) are not fragmentary (like Eupolemus, Ezekiel the Tragedian, etc. – these are readily available in Holladay anyway); and c) are probably extant in their original language of composition, Greek, we could include (z.B.) the following (even if the first two or three and some of the others may be Christian in whole or in part):
Ascension of Isaiah
Joseph & Aseneth
There’s of course the SC volume for Aristeas in French/Greek, and various editions of the others as well, but can’t quite think of anything else that does facing pages of this stuff in English translation, and it would be useful, I think, to have this gathered as a corpus.
A more ambitious undertaking would be a sort of Studienausgabe multi-lingual edition of the OT Pseudepigrapha. For students of the New Testament and Second Temple Judaism, we have facing-page bilingual editions for Philo and Josephus in the Loeb editions, for the Dead Sea Scrolls in the Martinez-Tigchelaar and Parry-Tov editions, for the deuterocanonical books in the traditional LXX editions, but access to the original languages of the pseudepigraphical literature often requires many different and expensive books, sometimes prohibitive even for smaller libraries. Nevertheless, the study of this pseudepigraphical and apocryphal literature has blossomed over the past thirty years or so, no doubt in part due to Charlesworth’s two volume OTP. Might it be time to give serious students of the period a handy edition with original languages and English translation on facing pages? This might especially be so as much of this literature is outside the range of other modern language editions like the Sources chretiennes.
Of course, one of the complications of this type of work is that the documents are extant in a variety of different texts and textual traditions, and some difficult decisions might have to be made as to whether, say, a text that is extant in both Latin and Ethiopic should be displayed in one or both languages, etc. But it does not seem that such difficulties need be insurmountable, and even a less-than-perfect-in-every-respect edition would be better than what we have now. And even if most NT scholars are not highly proficient in languages like Ethiopic, the ability to do a bit of checking with a lexicon and so to increase the certainty of one’s own research would be a welcome advance. If relevant copyrights could be secured, etc., maybe it would even be possible to use some of the same contributors from Charlesworth’s volumes who could supply both original text and translation. Or one could attempt to extract text and translation from the de Gruyter Commentaries on Early Jewish Literature project.