So, my PhD has been submitted and I can wait for the paperwork to advance and then the date of the viva...
While I always supported making the code available - and it was on Sourceforge as a zip-archive - (minus the Intel ODE library which must be downloaded separately), this has become official with the library recommending Github with Zenodo to create citable code.
Hence my Chemical Kinetics Solver has found an official home here:
Of course the code comes with no given or implied guarantess or warranties - i.e. use at your own risk.
Once my thesis has been defended (and assuming all goes well as expected), it will be available on the White Rose eThesis Archive which contains some minimum instructions on how to run the code.