The mark "P 14 K" could be the sponsor mark, including the 14K. In other words, the "14K" serves the purpose of the sponsor mark and the gold standard. There is actually a US sponsor mark 14K - P. & A. LINTON Co. (on 14K Gold Filled & Plated Band Rings, Manufacturing Jewelers, Providence, RI, USA) - ca 1887 - 1908.
I had a very quick search and had no luck with the P before the 14K
I would take the wedding band down to your local jeweler and ask him to acid test it for you. It shouldn't cost much. There are some really ambiguous marks on gold colored metal, not to say that your band is necessarily gold plated.
For instance, they used to advertise 14K gold plated rings, in a 1898 Chicago advertisement - "Fine Gold Shells Rings" - (How to be a Jewelry Detective by C. J. Bell) which are in reality all gold filled, so anything is possibly.
Acid testing by filing using the longest, thinest, sharpest-edged testing file, in an inconspicuous spot. Never use a long file mark as it will not only damage the piece but it will also diminish its value.
This is the only way you can be certain unless you have digital gold testing equipment that can read plating. Some gold testing equipment can determine gold plating.
Don't forget the "heft" or weight of the ring and the antique store of value affects the price.
