Good morning (to us) Zardov. I've just arisen, cup of coffee to hand, and I've printed off this page so I don't miss your queries.
31d. Seems to be a variation of an instrument that an Australian called Shirley Abigail usd to play - a zither, but here of course the first letter is different.
32a. Chambers gives "purl on" as upset something. Never heard it used that way before - can only assume it's the reverse of "plain" in knitting.
27ac ape - copy, poco - little.
7d jazz - trad?
6d - I do't get the wordplay either - I'm sure womeone will enlighten us.
Incidentally, the one I had a bother with (well, one of them) was33d. Strangely enough, it worked with either a or o as the second vowel - including the extra letter.
Any more?