Hi Nell!
Thanks for the suggestions.
Various records point to the families of George, Thomas and William in Sandford from 1835, when they began recording (sometimes) the name of the hamlet rather than the parish, to about 1868. Sandford is now gone, but in 1841 it was a hamlet of about 25 households. It's possible that three unrelated Kendall families lived there, but I figure it's worth looking for a connection.
What I'd like to explore is the possibility that Thomas (c.1761) was a son of George (c. early 1700s), and that William (c.1784/5) was a son or nephew of Thomas, but that both baptisms are either missing from the transcriptions or occurred in another (nearby) parish.
It may be a long-shot, but as I've searched various records, I've found records that were missing from other sources. And I have a sneaking suspicion that some sources are based on transcriptions rather than originals, as I've found some of the same errors in both. I've been seriously considering purchasing a set of fiche for the parish registers of Ringwood Union!
Thomas married in 1785, baptised two children in 1791 and 1793, and was buried at the parish church in 1847, age 86. Of course, it's possible he was non-conformist and that he "converted" when he married, but there's no mention of him in any of the non-conformist registers I've seen. (I've also found no trace of the burial of his wife, Amy Hatcher. The best I've come up with for her burial is Emma Kendale, buried 1837 age 76 in Sandford; so far, I've found no other Emma of that vintage in the records.)
In the census, William said he was from Sandford while his wife was from Ibsley (which I've confirmed). Again, not proof that he really was from Sandford, but worth considering.
I'm reading a book on Agricultural Labourers that says they rarely moved more than about 30 miles in a lifetime, so an expanding-outward search seems the way to go

As far as looking at Dorset, I've looked at the IGI, but there's nobody within 10 years. There are probably better Dorset sources (I'll look into that later), but if I were to find a Thomas Kendall, even within a year or two of 1761, I'm not sure how I'd be able to connect him.
Regards,
David