I have a free application where you need to create an account or use facebook. A one time in-app purchase allow to "unlock" the app (remove ads, additional features...). Classic.
When logged and not yet purchased (ie. locked), I display a button "Unlock VIP Pass". This open a dialog with "Purchase for $XXX" and "Restore Previous Purchases". Note that when the purchase or restore is done, I store bought product ids in a file.
When the app is purchased (ie. unlocked), I prefer to not display this button "Unlock VIP Pass". In this case note that no "Restore Purchase" are visible in the application.
Also note that when not logged, no "Restore Purchase" are visible in the application.
I know that Apple ask that applicaiton with in-app purchase must have a "Restore purchase". Does that means that this button must be available in any situation ? or does my description is enough (ie. restore only visible when the do not find the purchase) ?