Hey Simon, I'm sorry my friend, my initial response to this question may have been made whilst I was somewhat "tired and emotional" at the end of a very long day. We didn't actually get any nut files in as samples, but I agree this is something we will look at adding in the near future. To be honest, the ones available from this company looked a bit cheap and nasty... but that could just be their photography.
The tools are really taking off (I only added them the other night). We have a dozen order already, most for the kits; with a combo of tools.
Obviously this will be an expanding product range; although I do want to steer clear of high end, boutique Luthier Tools.