You may need to rip them to your computer first and see about re-saving or converting them to a file that will upload. Nero ($) or HandBrake (free). Handbrake is meant for processing video, but it can do other stuff. Also VLC.

Those Mudcat CDs were produced in small batches on machines meant for duplicating the disks onto regular (but good quality) blank CDs, so they probably don't read quite the same as commercially produced audio CDs.