What items would i need to upgrade this bow to legendary status? I can't seem to find exactly what i'd need anywhere.

Just go to a workbench and check.

Besides the perk, and ebony ignot i mean.

As in enchanting. I don't know if i'd need maxed enchanting or not.

If the bow is past a certain level (46 i believe) it won't work as those items are scaled with the player.

It is 46. I recieved it at 49.

I was under the assumption that if i was able to acquire +100% smithing on top of my already 100 skill in smithing, i'd get a legendary Nightingale bow. Not possible?

The weapons like that are scaled to maximum if the player is 46 or above and it cannot be upgraded beyond its maximum. Not sure if it was intentional or a bug.

Okay, thank you.