According to Wikipedia, this site, and etymonline, third-rate derives from a term related to ships, particularly a rating system in the British Royal Navy.
However, etymonline dates the term to 1814, while this site cites Wikipedia, and Wikipedia attributes the term first to "the 1720s," but later describes the rating system as originating in 1620.
But the earliest actual citation I can find is in the OED, which gives no explanation of the contextual development of the phrase, but provides a date earlier than etymonline with a context to which I am unsure the British Royal Navy relates, because the publication is about housing and land.
third rate n.
1656 H. Phillippes Purchasers Pattern (1676) A iv b An house of the third rate.
This citation is all that is given for the compound "third-rate" in the online edition of the OED, there is no definition provided or additional notes.
Does the OED's declination to attribute the term to shipping in combination with a lack of citations related to shipping that antedate the citation related to housing and land indicate that the direct connection to the British Royal Navy is dubious?
Is there evidence that "third-rate" referred to ships before it referred to houses, as Wikipedia claims without in-line citations, while providing no cited texts using the term? Or are there other reputable sources that establish the validity of the British Royal Navy connection -- particularly sources that might help explain the OED's lonely attestation?