I remember this happening in halo reach as well, the only way the coordinates would work was if you were on the original profile that was used. So yes you would have to use liberty to change your coordinates but its worth the armor and visor.
You could use this to get the armor, but there is a chance of ban by using it. http://www.xpgamesaves.com/topic/59002-halo-4-profile-modder-xbox-360-modding-tool
For noobs like myself it would be extremely helpful if you posted a new youtube video up of you successfully using the liberty tool to mod your campaign.
Thanx man, great job. I have noticed that this save also has 946/1000 limbs dismembered. So 54 more and another quick cheevo.