You're missing DynaLoad string symbols

Here's some documentation on them: docs.donutteam.com/docs/hitandrun/misc/dyna-load-data

You basically need to add a ";" at the end of the ones you're loading and a ":" at the end of the ones you're unloading.

For example:

Game.SetDynaLoadData("l1z1.p3dl1r1.p3dl1r7.p3d")

Should be something like this:

Game.SetDynaLoadData("l1z1.p3d;l1r1.p3d;l1r7.p3d;")

Ah that's a real shame,

Well not to worry, LUA it is then in that case, now hopefully I can find a good example project to figure out how I'm structuring this thing, been struggling to find a decent LUA guide for these mods / hacks,

Thanks anyway!

Nope, without LUA there's no way. You could make multiple versions of the same mission in MFK and have a LUA script decide which version to execute, but in my opinion, you're better just having your mission as a LUA instead of MFK