Andy,
I've been messing more with your ANDY10 file. I enjoy doing this sort of thing. Recovering data from damaged accounting system files was something I did 'professionally', so this is 'fun', with the added pleasure of listening to the results.
Firstly, I used the option within SynthFont to save the sound to a .WAV file. Your 'song' is 2m 58 secs, and this creates a .WAV file of 31 Mb, and when I check the file I note that the parameters indicate that it's CD quality (1411 Kbps, 16 bit, stereo, 44 KHz). Unfortunately, the max file size for the forum is 2Mb, and using zip reduces the .WAV only a little (to 29 Mb). I could reduce the quality a LOT, but this would spoil the effect.
SynthFont shows that ch 4 and 9 have multiple Program Changes, but when I check the detail I find that this is an illusion. There is I think one only real change, the other changes are repeats of the original setting, and there are also invalid Bank Selects that will probably have no effect on my system (but MIGHT have done something on your setup). Under GM, a Bank select requires the Bank commands (controllers 0 and 32) to be followed by the Program Change, and it's the PC which effects the change using the previously set Bank settings. The data in your file shows the PC, followed by the BS data which means that the BS will have no effect.
Apart from that, your file shows a text description for the instruments used, and these are NOT always the same as the GM spec, so I do not know how different the sounds might actually be. Of course, they may just be different names for very similar sounds? For example, Channel 0 uses patch # 95 (0 to 127 numbering), called 'Polar Pad' in your midi file, but 'Pad 8 (sweep)' by SynthFont using the GM name ('Sweep Pad').
Anyway, I'm fairly sure that I am NOT listening to the music that you created - this is not YOUR fault, it the different settings between your setup (30 years ago) and my setup. Even so, it mostly sounds very good.
Geoff