Excuse the length of this screed, but just for the record:
In re: Harry Turner- the Telegraph website put up an updated version of the notice subsequently:
http://announcements.telegraph.co.uk/engagements/220663/mr-h.m.m.-turner-and-the-hon-c.r.j.-fitzherbert
This provides his initials, and based on records I've concluded him to be Harry Michael Mortimer Turner, b. 1990. His eldest brother is Frederick James Mortimer Turner, b. 1985, who married Hon Harriette Jane, dau. of 3rd Baron Cayzer. The birth of their daughter Isobel Molly in 2016 was reported here by Richard R., as was probably their marriage. For completeness's sake: the second son is Maximilian ('Munchie') George Mortimer Turner, b. 1987, who m. Kate E. F., dau. of Robert Moyle, of Woodside Cottage, Prestwold, Leics., and the youngest son is Thomas William Mortimer Turner, b. 1992. The birth records give mother's name as 'Weir'; whilst I couldn't find the birth of a Diana M. St A. Weir, company records identify her (b. 1960), as well as her marriage record.
After some (admittedly fairly laborious) looking through different sources, it appears 'Michael Turner' of Aldeburgh is Michael John Turner, b. 1951, a chartered accountant, and formerly managing director of Fuller Smith & Turner, the brewers, now a non-executive chairman. He is (according to brewery history and publicity) a fifth-generation descendant of John Turner, one of the founders in 1845, details of whom can be found all over the place online (also see below). The main confirmation point was, based on social media, evident cousinship with the (in one particular case very distinctively-named) children of a Timothy Turner, of Aldeburgh; double-checking birth records for shared parentage and place of birth for a Michael J. (b. 1951) and Timothy J. M. Turner (b. 1949) identified their mother as 'Healy'. Company records for a Timothy James Mortimer Turner b. 1949 show him to be a solicitor, and company director for Fuller, Smith & Turner brewery amongst other related concerns, which I think conclusively identifies Michael Turner also.
Regarding their parents: the marriage took place in 1947 of Gerald Mortimer Turner (1918-1990), of Wood Cottage, Ashtead, Surrey, educ. Peterhouse, Cantab. (B.A. 1939, M.A. 1943), 2nd Lt, Royal Green Jackets, and Joyce M. I. (née Healy).
I should imagine, given the 1918 birth record for a Gerald M. Turner, mother 'Mortimer', that the marriage in 1914 between Walter E. Turner and Ethel C. Mortimer at Saffron Walden, Essex is likely that of his parents (given the lack of other options), but it'd need confirming; I'm sure it's perfectly possible to trace back to John Turner, but it'd take a little more time than I have at present, and there's no real reason to doubt the statement given the family's clear involvement in the business, so I don't know it's worth the effort!