My research has now moved on to the second part of my Grandfathers war service when he was transferred from the infantry to the ASC. I have finished re-reading Michael Young's 'Army Service Corps 1902-1918' the ASC bible and have made significant progress today.

First the unit he was transferred to was 801 Co ASC MT this unit was the 16th Corps Troop Supply Column. 16th Corps were the divisions based in the Struma Valley and the Corps Troops according to 'Under The Devils Eye' were the 1/1st Surrey Yeomanry. So my Grandfathers unit was responsible for transporting supplies from the Railhead to the Refilling Depot for collection by the Surrey Yeomanry.

A quick look on the LLT website revealed that the Surrey Yeomanry were a Territorial Cavalry Regiment and 'A' and 'B' Squadrons were indeed based in Salonika.

The next task for me is to try and figure out where the Railhead was (probably Snevce), where the Refilling Depot was and where the Surrrey Yeomanry were.