Hi Steviemac,
If you have a cabinet already, unless you are CERTAIN its going to fitted properly, wait until the FEO interviews you and ask his advice. I am sure the guys down in K division will be very reasonable and will not mind having to call again to ensure cabinet is up to standard and fitted to the struture of the building. Details of the type and capacity of the cabinet will be noted and kept on file.
I had a story related to me where the cabinet was poorly fixed to a gyproc wall inside built in wardropes. The door of the cabinet was lying open and with one hand the FEO tugged on the door and 2 small spring toggles came through the gyproc and the entire cabinet came away from the wall!
The potential certificate owner looked at the cabinet and the FEO and said "They Barratt builders are a bunch of cowboys!"
Good luck with your interview anyway.