Can't seem to understand 9dn--I'm only missing the unchecked cell and I can't find a way to complete the word that matches the part of speech and tense in a way that makes sense to me.
Spent an hour and a bit thrashing around in total confusion, then a very simple canter to the end once the penny finally dropped. Also couldn't parse 42a but makes sense now after the hint.
That was straightforward enough post PDM (which for me came very early) but I think there may be a word missing from the clue for 9d. Isn't this an obsolete spelling, which should be indicated as such?
I think 4d is an adverbial form rather than an obsolete one. (But I may be getting dangerously close to counting grammatical angels on a pinhead…My wife reminds me that it has been known!)
Personally I quite liked this. I think the setter has used all the thematic answers meeting the necessary length criteria. And I thought 27 was a very good clue of its kind.