Limp along, then stop by Mill Square near Oxford with a small railway station (5,2,1,4)
I believe the answer is:
grind to a halt
'limp along then stop' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'mill square near oxford with a small railway station' is the wordplay.
'mill' becomes 'grind' ('grind' can be a synonym of 'mill').
'square near oxford' becomes 'to' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' means one lot of letters go next to another.
'small railway station' becomes 'halt' (I've seen this before).
'grind'+'to'+'a'+'halt'='GRIND TO A HALT'
'by' is the link.
Can you help me to learn more?
(Other definitions for grind to a halt that I've seen before include "Slow to a standstill" , "Cease to make progress" , "Slowly become stationary" , "Come to a standstill" , "Run out of steam" .)