If anyone comes across this when trying to mod older games, I've gone ahead and created a standalone Windows desktop application based on the Java version here. Feel free to test it out, I've only ever tried it with Immortals Fenyx Rising and it worked well there.
Download Link:
https://github.com/srobertson421/Resorep-Tauri-Application/releases/download/v0.0.1/resorepv0.0.1.7z
Should be able to simply extract the 7z file and run the .exe. It functions similarly, click "Add Game" and find the .exe for a game. Add a folder path to both the "modded" and "original" fields and you should be all good to add your texture mods to the "modded" folder.
All credit goes to Ray Wing for the initial version!
Thanks for the review, 70 persons downloaded the example image without telling me...