It now appears to have been cleaned. If you TPG it, they will most likely will state that on the slab and will grade accordingly. I would slab it and enjoy having it in my collection. All Morgans are keepers! Thanks for sharing before and after photos.
Probably in the XF45 range, but it does look like the grime may have been hiding some problems. If you're determined to certify it, I'd suggest Anacs or IGC.
Here's an 1878, 8 tail feather dollar in MS-63, my grading. I have never had this piece certified because I don't think it would be worth the expense. Besides that, I like it think it looks better to me in this set holder of 1878 Morgan Dollars.
That has only changed in recent months with the significant increase in the price of Morgan Dollars. I have owned that piece for over 30 years, and for most of that time, it has had the value to warrant certification. Even now, given the high price for shipping both ways with insurance and the grading fees, it’s marginal.
Your coin, your choice. I'm just showing you right off the price guide reasonable people might see it different.