They were not commissioned by Harvery's though I believe they have been used since to produce some images.
I emailed them to ask if they had any tips, to see what worked well for them and what didn't. Catherine kindly replied to me stating that light was indeed an issue as I had first thought. They shot almost exclusively with natural light and reflectors. A good tip was to set up any arranged portrait shots ahead of time to minimise disruption to the workers. This is excellent but as they were two people, perhaps one as a temporary subject to check light, I think they would have found this easier than I will.
'Don't forget a tripod...' that was another great piece of device - I will in fact take everything I own as I will be driving it is no problem to fill the boot up.
Catherine and Sarah's images are very high quality, they have given me inspiration with the subject matter, indeed Catherine stated in her email that there are lots of opportunities at Harvery's so I am looking forward to it. Watching their promotional video also has given me some ideas which I will combine ahead of time in a list. I also need to take a notebook to make notes of the people and subject matter as well as recording other potential ideas as I go along. I have two mornings to shoot so there will be some opportunity for revising the material.
Bensonweal's images are more contemporary that I was envisaging on taking for the brief, but I will try and incorporate some if the opportunity arises. Their use of the little light is very effective though I notice a lot of clipped highlights in their images...given the low light I think this was avoidable. Thanks to Catherine for replying and for giving me more ideas and confidence.