If you read back a number of pages in this very thread, I put up exactly how to do Dual Mining on Gridseed Orbs (Minis) with also having an Antminer U1 on there.
The Dashboard in Minera pulls its data from the API provided by the mining software (and of course, modifies settings using that api), so currently it isnt possible to control/display more than one mining instance.

Having read your guide, you edited rc.local directly with nano, on a standard minera install, this will not work as a reboot will delete your changes. You have to put your rc.local commands into the rc.local section of the Minera Dashboard Settings page.