19a Tar present, chemically, in china clay (4) ?a?t
20d Old soldiers releasing king from shackle (6) ?e?i?n
Also two answers I think I've got right without understanding the word play:
18a Composer, initially losing one near perfect score (6-4) Answer Ninety-Nine?
22d Like highly driven person, start autobiography? (4,1) Answer Type A?
Thanks for you help!