Check out Christian's post from 19th May:
You may also find the download logic file to be of help, although it doesn't seem to have a patch list for the Motif Classic.
I've also managed to find an environment specifically for the Motiff Classic:
If you don't want to register with that site, no problem, let me know & I'll post the Motif Classic files (with instructions) so you can download them from here.
Hope that helps,