Seize money from Cape Town banks using small keys found on me (4,5)

I believe the answer is:
baby grand
'small keys found on me' is the definition.
I can't judge whether this definition defines the answer.
'seize money from cape town banks using' is the wordplay.
'seize' becomes 'bag'.
'money from cape town' becomes 'rand' (I can't justify this - if you can you should believe this answer much more).
'banks' is an insertion indicator (bank can mean to surround or border).
'using' becomes 'by' (I've seen this in other clues).
'bag'+'rand'='bagrand'
'bagrand' enclosing 'by' is 'BABY GRAND'.
Can you help me to learn more?
(Other definitions for baby grand that I've seen before include "message of proud new parents?" , "Smaller piano" , "Type of piano" , "Instrument" , "Infant piano?" .)
