I think the reason I didn't patch this for widescreen was due to bugs/issues during testing, though I can't remember though, sorry

If you want to do it yourself you'll need to patch the WS pnach directly onto the ISO. First;
Code:
https://forums.pcsx2.net/Thread-PCSX2-Widescreen-Game-Patches?pid=271674#pid271674
That's the patch archive which contains all known WS fixes for all available titles.
Code:
http://psx-scene.com/forums/f19/ps2-patch-engine-117652/
That's the tool you'll use. Just drag'n'drop the .PNACH file into the GUI, then drag'n'drop the game ISO and hit patch. Good luck!