On the 1979-P there is a near rim/wide rim coin:

Upper image. (only on the business strike Philly SBS dollar) Those with the lower image are the common ones.
On the 1979-S Proof there are the filled S (type 1) and Clear S (type 2) mint marks.

The valuable one.
Your coin is a business strike 'S' which is common. (It has the filled 'S' {type 1} mint mark)

Upper image. (only on the business strike Philly SBS dollar) Those with the lower image are the common ones.
On the 1979-S Proof there are the filled S (type 1) and Clear S (type 2) mint marks.

The valuable one.
Your coin is a business strike 'S' which is common. (It has the filled 'S' {type 1} mint mark)


























