I may or may not be slightly crazy. Since I couldn’t find anything to renumber generator parts files that works on Linux, I’m scripting something up to run via terminal that’ll do the job. (Face is done (and was a fustercluck-and-a-half), and I’m taking a well-earned break before tackling SV, TV, TVD, and Variation. @.@)
I fixed my little itch.io issue... apparently filenames are case-sensitive. After I renamed the file IconSet.png instead of Iconset.png, it worked. I changed it back and forth a few times just to confirm this.