Manual Update Option not available

[gordc]

I currently have two c2758 systems that I am building to put into production running 2.3
I wanted to update them to the latest version but I am not sure how to do it.  The system currently do not have internet access and won't till I move them in to production.
When I go to the update page I get a message that states the system is up to date and I don't have any options for updating the system.  So now how do I update them

The following is what I have tried so far.
I have gone over the upgrade instructions a number of times but I don't get the options indicated. 
When I go to system/updates.  It just tells me that the system is up to date and I have no options
When I go to the cli and use option 13, it runs and shows it is trying to check the internet for an update, fails and stops.

There has to be a way to update them without doing a backup, full install and then restore.  I have had issues in the past with doing a restore and would prefer to avoid it.

[phil.davis]

I would:
a) Save the config
b) Set to factory defaults (so you get DHCP on WAN)
c) Plug the WAN into an ordinary LAN (e.g. plain old office LAN at work) that gives out DHCP
Now the unit has internet.
d) Do the online upgrade
e) Restore the config