Assuming you are willing to take advice from someone who is in the possession of a mere History degree.
May I suggest that you create a template document, that you can the copy and paste when you need to make your requests.
Then you can modify the names/details as necessary.
I doesn't have to be overly 'wordy,' but starting something with the lines...
Should help you get a better response.
I know, you have deadlines, and you are stressed to high heaven, but businesses expect a certain level of behaviour with these things, or they just go in the bin.
If you've got anything you can add which may 'sweeten the deal' such as 'this research will be used to help the industry achieve....' - it's worth a go sticking that in as well.
Just don't make it too long.