Back to STEER for a moment. I fall all over them in the parish register films I have on perm loan at my FHC. Don't recall if Egham, Surrey, Westerham, Kent, or Feltham, Middx, or any combo thereof, but you mentioned Surrey, so....
Don't know when I can get back to FHC, but let me know if you want anything in particular looked up in those places.
Also, St George Hanover Square was not filmed by LDS, but there is a book of marriages that can be accessed on Google Books. Births were not done as a book. All the parish's records are held at the Westminster Archives.
You guys are awesome! Good luck on this hunt, Kerry!