ttrap,
You should not need an older version of software to get the newer software for the iPilot Link Controller and Remote to load, so there may be something else going on here but I’m not sure what that could be. I would call Humminbird Customer Service back again and let them know that was not the solution to your problem.
BTW: older software versions that worked with the 1.160 iPilot Link software were 6.600, 6.610, 6.640 6.740
The Humminbird Customer Service folks should be able to look up the original software version for you by the unit’s serial number.