Collector's item in US city filling empty satchel on seat (5,5)
I believe the answer is:
stamp album
'us city filling empty satchel on seat' is the definition.
I can't judge whether this defines the answer.
'collector's item' is the wordplay.
'collector' becomes 'stamp collector' (stamp collector is a kind of collector).
'item' becomes 'album' (I am not sure about this - if you are sure you should believe this answer much more).
'stamp'+'album'='STAMP-ALBUM'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for stamp album that I've seen before include "Something used by philatelists" , "collector's book" , "Philatelist's book" .)