Why have it graded? If you are happy with the piece leave it be. No point in torturing it further by sending it to be tombed. The gash suggests it has already had enough trauma.
I'm leaning towards a 'yes, it will go into a graded slab'. Coins with a gash in their surface get graded all the time, but obviously at a lower level.
I think they may take the entire coin into consideration before deciding whether to bag it or not. What does the obverse look like?
Rev has a bit of damage but if the obverse is as good a photo of Rev .rim ding may not lower to as Kanga has said. Slabbing I would not send it to Pcgs all the other 3 are a open $ wise maybe better on wallet
Beautiful coin, gash or not. I would send it to a tomb just so there isnt any issues about being fake in the future.