Ballast and engineer trains on The Far North & Kyle lines

[GmacD]

Hi folks,

 

Am modelling the far north line in the period 1955 > 1962 and am looking for information regarding the types of wagons used for ballasting and engineer workings (any crane vehicles used too?) on the far north and Kyle lines in the late steam early diesel period. Am unable to find anything much at all other than 1980s era pics with class 37 and 26 hauled stuff. 
 

If anyone has input on this subject it would be greatly appreciated.

 

Thanks