The 1914-P sovereign was struck at the Perth mint as denoted by a P mintmark on the exergue above the date.
Like most Perth mint sovereigns are reasonably easy to acquire in circulated grades but finding examples in mint state, particularly at the MS64 level or above can be a real challenge. Like most Perth mint gold, strike depth is a limiting factor on the grade though at least one hoard of mint state examples has surfaced in Adelaide which appear to have been struck from a very early die state providing both well struck examples with the quantity required to make examples with good surface preservation possible. That being said, the finest to have been certified from this hoard are still only grading MS64. (PCGS, 2017)