Couldn't you dump your roms from the web browser gateway launcher? You'd need a 9.2 3ds though (and actually own the physical cartridge)
Could you use headers from different 3ds roms? (I don't know if it'd actually work) Take header from pokemon rumble and put it on mh4u? You probably have at least one cartridge laying around.
Unless OP's specify their system version, I just assume they (sky3ds users) scream YOLO and actively do system updates to the latest.
You make a valid point that this user could be on an earlier sysnand version and your suggestions make sense to me.