Hi, catkin,
In 33dn, the definition is “polish”, though it’s rather obscure (but verified by Chambers). The first three letters of the answer are a part of a vehicle, a word used by Shakespeare (hence reference to Stratford), and the last letter is the standard abbreviation for East. I got the answer after slogging through possibilities in Chambers, at least I didn’t have to go far down the alphabet.
There are six missing letters in the top right corner, two of which come from 20 ac. The wordplay for this clue gives the first three letters of the answer. It’s a similar trick to 33dn: you have to read the wordplay as “South” + “American city contracted”.