Marriage confusion

[Lindsay]

I'm puzzled by the results I'm getting for this marriage...

Familysearch have a marriage for Philip Stambury/Stanbury and Mary Martyn, 1717 Devon. The image is only viewable at a family history centre but it says 'courtesy of FindMyPast'. I can't find any trace of it on FMP.

There's also no trace of it on Ancestry via a normal Ancestry search, but if I google the two names I get to the Ancestry Historical Person search (whatever that is) which has this:
'Born in Bratton Clovelly on 10 Jun 1683 to Benjamin Stambury and Mary Caddy. Philip married Mary Martyn and had 2 children. He passed away on 22 Jan 1753 in Stowford. '

It reads like info scraped from family trees, but the only trees which seem to have the marriage are private. Has anyone else come across the Ancestry Historical Person search?

And does anyone know why Familysearch mention FMP if FMP (apparently) don't have it?