Never heard of a game larder audit? But it might just be a difference in terminology.
I set up my food business 2 years ago. All I do is supply venison in fur to game dealers (AGHE), supply venison skinned whole or into primal cuts to restaurants/pubs and whole skinned carcasses to butchers, plus a small amount to the public.
I don’t have a retail front, just a larder and chillers. When I set it up I went online and registered as a food busisness, contacted the local environmental health department and talked through the requirements and set up the larder accordingly. The basic physical requirements included hygienic wipe down walls and washable floors. 2 sinks, one for hands and one for utensil, both with fresh water hot and cold. clean and hygienic working surfaces, adequate light, food standard first aid kit, food safe cleaners and sanitisers. In terms of paperwork, I was required to have HACCP plan that covers all stages of the process including preparation to hunt, extracting carcasses, vehicles, refridgeration, chemicals used and delivery etc. Here is a link to HACCP
How to manage the food hygiene and safety procedures in your food business.
www.food.gov.uk
I would try to get an accurate view of what the audit involves as it gets expensive and time consuming if you need to go the whole hog!