... but two in this case find Peterhead has atmosphere (4)
I believe the answer is:
pair
'but two in this case' is the definition.
The definition and answer can be both quantities as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'peterhead has atmosphere' is the wordplay.
'peterhead' becomes 'p' (head letter of 'peter').
'has' means one lot of letters go next to another.
'atmosphere' becomes 'air' (synonyms).
'p'+'air'='PAIR'
'find' is the link.
Can you help me to learn more?
(Other definitions for pair that I've seen before include "Two of a kind, as in cards" , "Twosome" , "how braces come" , "Twins" , "Agreement to avoid division" .)