Marty I scraped the MTH Website a while back and grabbed EVERYTHING. Manuals, schematics, and every single sound file. People talk about 100's of MTH sound files, it's more like 10's of thousands. The MTH sound Library is currently free and public, If you are worried, go get em now I say.
Great minds think alike!
I have downloaded all the sound files I wanted/needed for personal use, manuals for engines I have, and all the catalogs. It all comes to a cool 9.42GB. I have backed this up on two thumb drives and a 2TB solid-state external drive. I have one of the thumb drives at a relatives house heaven forbid there was a fire or some major catastrophe.