... and back, into a Mitford-approved vein to the point of producing disgust? (2,7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

AND reversed (back) contained in (into) ( A + U [During the 1950s, Nancy Mitford [1904 – 1973] developed the concept of “ U ” {upper} and “non-U” language, whereby social origins and standing were identified by words used in everyday speech] + SEAM (vein [of ore, for example])