Does your inverter have power pass through in the event that shore/generator power is there to use? Let me know and I will sketch you out a diagram and E-mail it to you if I can
If not it's a bit easier I can describe that with words (In fact I think I did)
If that inverter is 1750 watts (about 15 amps) you will need a small breaker box or 120 volt power distribution panel (Progressive Dynamics makes an excellent one, use the 30 amp box) A short heavy duty (10ga) cord, a 20 amp TWIST LOCK plug, and two 20 amp TWIST lock outlets. (NOTE You may wish to use 30 amp Twist Locks)
You will need a longer "Cord" (power line) and a plug or plugs matching your inverter.. More on that later
First, install the sub panel (The above described breaker box or power distribution panel) near your existing one. Move all the loads you wish to have on what I will refer to the "EMERGENCY POWER" panel (That is powered by the inverter) to this panel, If you get the same make or style you may be able to just unhook the wires, and move the original breakers. (This makes it easy) though you will want somethign to replace the original breakers with in the original panel (Blocks of wood, plastic, electrican's tape on the cover, all work)
Now, for the power in to the panel hook your short cord with the 20 or 30 amp twist lock PLUG (male)
Hook another short cord from a breaker to a matching outlet,,, NOTE The breaker (which you will have to buy) should have the same rating as the plug, 20 amp plug, 20 amp breaker, 30 amp plug 30 amp breaker, Note also that the total of the load breakers in the sub panel may be greater than the supply breaker.
Now, put a 2nd outlet labeled "Inverter" next to the first (Which I'd label "Shore") Run a line from this one to the inverter where you install a plug matching your inverter... Special case, if the inverter has only a single duplex outlet then I'd either install a double male on that end wraping paste epoxy around the plugs to insure they are only plugged into the inverter's outlets or I'd wire direct inside the inverter (Depending on how easy the later is to do) or I'd use a dual 15 to single 30 amp RV adapter (If you can find one) and a 30 amp RV plug at this point.
And that is all there is to it,, The Emergency powered loads can be plugged into either outlet at the transfer point.
Another way to do the same thing is to replace the two outlets and one plug with an Automatic Transfer Switch (Much more expensive, no safer)