Rate isn't adjusted for toy railway (5,3)
I believe the answer is:
train set
'toy railway' is the definition.
(I've seen this before)
'rate isn't adjusted' is the wordplay.
'adjusted' indicates an anagram.
'rate'+'isnt'='rateisnt'
'rateisnt' with letters rearranged gives 'TRAIN-SET'.
'for' acts as a link.
(Other definitions for train set that I've seen before include "Strange treats in store for this model toy" , "A child might play with this" , "Nitrates (anag) - Hornby product?" , "Model tracking" , "little loco with this?" .)