Assuming that the VIN has allready been checked and confirmed that it is an actual Indy Fiero, it would appear then that this Indy has been thru a lot of changes. Especially as you stated and we can see that the rocker panels were taken off and or swapped with regular ones, had the deck lid swapped with a later model, some panels were replaced and or painted, smaller non Indy fader red stripe was added or replaced, etc, etc.
With all the recent people we have seen taking non Indy Fieros and putting Indy interiors in them, putting Indy badges, stripes and decals on them and so forth, you just can't go by looks alone much anymore.
It looks however as though you won't need to do much to get that Fiero ready for some shows this year

Nice buy.
When you get that baby on the road, we should cruise our two Indy's together, maybe to a few shows?

Steve