Leo referring to the Shtat diagram at the start of this thread.
The structure of the Division is laid out in its chain on command and the small units of the division are shown in their subordinate places. This layout is followed in the Staff of the Division Shtat 04/550. In this scheme the small units such as the Bank, Post Office and Vet Hospital are shown in the top right hand corner under the "Deputy Divisional Commander of the Rear" and under the "Department of the Rear Services". The balance of the small units are shown in the top left hand corner under the Staff and draw their rations from the only sizable unit in the staff, the Signals Company. Similarly the only sizable units of the Department of the Rear are the Medical Battalion (91) and the Bakery (55) and the Motor vehicle company (88) but the only one at the Rear HQ is the Medical Battalion, so I would imagine that their mess fed the staff, the bank, post office and vets. This follows the structure of both the Front and national Rear Services which were responsible for these areas