My thoughts exactly, Dobby. I realize you are probably weary of this topic by now, but other readers may benefit from a recapitulation of all the facts we have analysed.
Since reading your last post, I have thought very deeply about the possibility that my hypothesis had been unrealistic. So I reviewed my files again. I also put it to a very skeptical friend of mine. The only fact which gives us pause is the long span of years between the births of John North (1698-1783) and Ruth North Broadbent (b. ca. 1774). But there are a number of facts (and hints) which tend to outweigh that:
1. Although I'm aware that some of the old tombstones in the Kirkheaton churchyard have been moved, yet it seems quite a coincidence that the stones of the Norths of Coldroyd and the Broadbents of Coldroyd and some of their descendants all found their way to the same location. The Broadbents whom my ancestor left behind in Dalton and Kirkheaton were very studious people, very conscious of their heritage, and seemingly very much attached to the fact that Coldroyd was the ancestral house. I suspect they would have at least observed, if not become involved with, any movement of monuments, especially those Broadbents who dwelt very near the church.
2. As you point out, the name "Ruth" is a strong hint. While not an unusual name, "Ruth" is not extremely common either. It is very likely that a son of Ruth Pollard North would have named his daughter for her; it certainly follows the naming patterns widely employed in the XVIII. and XIX. centuries.
3. Coldroyd! I notice that the parish register often refers to the Norths "of Coldroyd," including when the John (1698-1783) who now commands our attention was buried. And when John Broadbent (1795-1856)'s last-born child was baptized, she was listed as a daughter of John Broadbent "of Coldroyd Dalton." Although I believe at one point there were as many as ten families residing at Coldroyd during the Victorian industrial boom, yet I believe that in the Norths' days and early Broadbent tenancy, the place accommodated fewer families, not unlike its present configuration. Coldroyd is definitely the badge of consanguinity between the old Norths and my Broadbents.
4. Back to the old-time naming pattern: Ruth Broadbent named her second daughter "Elizabeth," which, if one follows the common naming pattern of that time, would suggest (though not prove) that Ruth North Broadbent's mother's forename was "Elizabeth" (the first daughter being "Sarah" for the husband's mother). And indeed we have one John North marrying ELIZABETH Balmforth just in time to have Ruth! And...we have the widow Elisabeth North remarrying to William Hirst in 1784 or 1785. This suggests to me that she was the widow of John North of Coldroyd (1698-1783), remarrying as soon as it was respectable to do so after his death.
5. While there are tons of John Norths around Kirkheaton parish during that era, the Coldroyd line itself seems to be pretty slender. I can find no trace of any children born to John (1625-1695) and Margaret North except Benjamin. And, oddly enough for those days, I can find no trace of any child born to either of Benjamin's wives except for John (1698-1783). That is almost unbelievable for that time period.
6. I am open to believing that Ruth (b. 1774) could have been the great-granddaughter of Benjamin and Ruth through another son's line, but such a line just doesn't seem to be there. I suppose that either of the Robert Norths whom you list as having sons John could possibly be a son of Benjamin, but is there record of Robert's baptism? I have not found any.
6. If John North of Coldroyd (1698-1783) was (first) married to Mary Senior in 1724, we can probably eliminate the John North son of John of Dalton baptized in 1721 as John of Coldroyd's son. Likewise, the John North baptized in 1739, of Ludgit, died in 1788, so he could not have been the husband of Elizabeth North, widow, who married Wm. Hirst in 1785 (although that doesn't necessarily mean he couldn't have fathered Ruth). And there aren't any other Johns who qualify as Ruth North's father in 1774.
Perhaps a will will indeed turn up which resolves this issue. Let us hope!
Thanks again!
Taddy.