I will download and check these tomorrow, but I don't think the flute and string trio versions are not arrangements. They are either alternate instrumentations for all 6, or it's a case of one or two of them, in which case we should notate which ones.
If the BNF oboe arrangements are uploaded, then the Arrangements header would take care of that instrumentation.
For now, the two tags that are there will take care of the original instrumentation, so nothing else is needed.
By the way, this is now under "A Second Sett of Six Quartettos, op.12", because that is what Grove Music lists as the original title.