If I understand correctly the songs are in various single files of 10 bank panel memory and you want to pick and mix from different files and combine into one 10 bank file?

If this is the case look on page 3 of the load page, select mode = panel memory, in the "from" box you can select a single bank from the thirteen A to 10, and in the "to" destination likewise a single bank. This can thus combine the panel memory banks of various disks.

Since you say composers are not present, the problem is sound memory. All the sounds will have to be in a single file and used from the same position from the source disks to require no action and this file loaded with the new ALL panel memory. If not page 3 of the load (mode = sound) can be used to combine single sounds from various disks and files into one 40 sound file, and then you just re-save the relevant panel memories to point to the correct sound of the original file.