Number One hit about Scottish holiday spot — one providing haven for Paul originally (3,6)
I believe the answer is:
top banana
'number one' is the definition.
(both can mean the most important person)
'hit about scottish holiday spot one providing haven for paul originally' is the wordplay.
'hit' becomes 'tana' (I can't justify this - if you can you should believe this answer much more).
'about' indicates putting letters inside.
'scottish holiday spot' becomes 'Oban' (Scottish holiday resort town).
'one providing haven for' indicates putting letters inside (inserted letters are given haven or sanctuary).
'originally' says to take the initial letters.
The initial letter of 'paul' is 'p'.
'tana' enclosing 'oban' is 'tobanana'.
'tobanana' enclosing 'p' is 'TOP BANANA'.
Can you help me to learn more?
(Other definitions for top banana that I've seen before include "Best of the bunch!" , "Big cheese" , "1" , "figurehead?" , "first on hand?" .)