A remake
Technology has caught up and so I have been able to re-record this from the original score with slight annotations to get a much more realistic string sound. I used a program called Musescore2 which was able to read the Finale file and play it back, allowing me to make various tweaks. The resulting recording was compressed in Audacity to make it somewhat louder. I have left the original recording in place so anyone interested can compare the two versions. Short of having it recorded by an actual string quartet, this is about as good as it will probably ever get. But it's a huge improvement over the older version.