A letter or two for transport (5)

I believe the answer is:

lorry

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'transport' is the definition.
(lorry is a kind of transport)

'a letter or two' is the wordplay.
'a letter' becomes 'l'.
'two' becomes 'ry' (I can't explain this - if you can you should give a lot more credence to this answer).
'l'+'or'+'ry'='LORRY'

'for' is the link.

Can you help me to learn more?

(Other definitions for lorry that I've seen before include "Large truck" , "From which stolen goods fall?" , "Load-carrying vehicle" , "HGV" , "Heavy goods vehicle" .)

I've seen this clue in the Evening Standard.

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