Help Identifying Hallmarks

[LadyGoodman]

These hallmarks are on a 18k gold diamond ring anyone have any leads or ideas? The ring was sold to me as Victorian. Looks to me like “hph 18ct 4” and I haven’t gotten anywhere in my search. I’d appreciate any help! Thank you!

 

[VRBeauty]

Could “4” be the ring size?

 

[blingmeupscotty]

The hph may be someone's initials.

 

[LilAlex]

Thinking maybe it is not "hph," I tried searching on "npn hallmark."

This is the best lead so far: