These were all in service by mid-1959,when frost grilles were being fitted to new Vulcan Foundry --and other---locos--e.g. the type 4's ( later Class 40) However,having looked at early photos of some ,I don't think you can be certain of the situation in every case. It appears that some carried them and some didn't..I saw all of them in service before their modification but after 50 years,the memory dims. Besides,I didn't know what a frost grille was. The dreaded '62--'63 winter was yet to come. It challenged the new 'Diesel Dawn' somewhat !