I can't really help, but I can tell you that I've got Yosemite in my App Store purchase tab, but I haven't been able to get Sierra to that tab no matter what I've tried.

Take a look at your /Applications/Utilities/Disk Utility sidebar; your Yosemite installer may show up there, and if it does, you should be able to run Repair Disk on it.

Worst case scenario, eBay has got plenty of listings for installers of all flavors of OS X...if you'd care to trust one of them.

Last edited by artie505; 06/25/17 12:57 AM. Reason: More
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