Small bank having lost pound or two? (7)

I believe the answer is:

slender

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'lost pound or two?' is the definition.
I can't tell whether this definition defines the answer.

'small bank' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'bank' becomes 'lender'.
's'+'lender'='SLENDER'

'having' is the link.

Can you help me to learn more?

(Other definitions for slender that I've seen before include "associated with 7 [MEANS] suggests modest income" , "Gracefully slim" , "Slim and supple" , "remote" , "Svelte" .)

I've seen this clue in The Sun.

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