Thanks for your help Frank.
The package downloaded and appeared to install correctly however the set-up beyond that point is unclear from the original instructions. I've tried to follow it and created a brutefir.config file from AllyCat's instructions but it didn't work and I'm out of my depth.
I have experimented with REW in the past and still hope that I can find a way to incorporate this in the Pi one day. Perhaps brutefir might be included in 0.4 with menu configuration.
All the best,
Trevor