Well I've got Gnomad2 working with the Zen now.
I found that the latest Gnomad2 and the libraries required to support the Zen's MTP were in the Fedora updates-testing repository so all I had to to was add that to yum's repositories temporarily and it all installed without problems.
Gnomad2 can now see the Zen and transfer MP3 files to it. It's a bit crude and simple but one huge amount easier to understand than the heap of rubbish that got installed on Windows.