Having this food company on your CV would ensure you always make it to interview stage in future, but famous companies do that don't they? This partially home-based account management role will also let you build relationships with other £multi-billion food companies, and you might even end up working for them after this contract ends.
The customer interface experience that you gained in your most recent QA, Technical, NPD or Specifications role would be what gets you this contract, not your food manufacturing experience or your management experience. Your engaging personality and confident manner backed up by your general food manufacturing knowledge would be what the interviews focus on, not a problem for you of course – this has always come naturally to you.
It's only 3 days per week on site or down with customers, so it's fine that it takes you less than a couple of hours to drive to the office in the West Midlands region – the £5K pro rata car allowance on top of the £45,000 – £50,000 salary helps too.
My client says their gut instinct is this will be a permanent role by next summer provided that who they hire demonstrates that Technical Account Management for their big customers is worth it for the business; that sounds kind of like a challenge, doesn't it?