1913 s type 1 with crud stuck on 3 in date - conservable?

[a.p.b-migration]

 

I recently acquired this coin and wanted to have it graded by ngc. When I looked closely at it,using a loop, I could see a lump of crud stuck in the crook of the 3 in the date. Is this something that could be removed through conservation? There is also a small black spot on the buffalo's back that seems to be of similar makeup. I didn't include a pic because I figured if you could remove one the other would get removed also. Please look at pic and give me your best educated guess. I really thought it was a good idea to look into conservation before grading.

Thanks,

A.P.B.