Lumen,
In 38a, 'original' can mean 'novel'. It's a separate anagram indicator for the word which is subtracted from the fodder.
37a. Def. is 'Scots lad' (5). Abb. for 'caught' + a word for 'guard' minus first and last letters. (out of bounds)
Did you mean 9d.? If so, it has an extra letter added on entry.