Many thanks to all who contributed to this thread, I have now had time to digest the information given and pass it on to my friend for his comments .....
In summary I think this is where we have got to
Baptism for all 4 children, parents Robert and Arabella Wiltsher (spelling varies)
Frederick Henry born 13.8.1887 and cr 16.6.1897 – living 203 Carlton Mews
Edward Thomas cr 14.8.1895 – 66 Harriet Mews
Florence Margaret cr 28.7.1897 – 203 Carlton Mews
Elizabeth May cr 11.4.1900 – 124 Shirland Road (address on 1901 census)
(Why R&A waited 10 years to baptise Frederick is a bit strange, maybe it had to do with the school or they suddenly got religion, we will never know)
School admissions for the boys (can’t find any for the girls)
Frederick Henry - 7.1.1895 St Pauls School, Westminster – 66 Harriet Mews
Fred H - 5.4.1897 St Augustines School, Westminster – 203 Carlton Mews
Edward – 22.2.1904 St Augustines School, Westminster – 92 Carlton Vale (106 Carlton Vale 1911)
Birth registrations in the name of McRae
Frederick Henry 1887 Paddington
Edward Thomas 1895 Chelsea
Florence Margaret 1897 Paddington
On Edward Thomas Wiltsher’s army attestation he states that he was born Chelsea, the family know a bit about his army career and have his number as 39763, unfortunately we have been unable to find his records on line due to the fact he wasn't discharged until 1925 so will have to apply for them.
The McRae connection makes a lot of sense now, as I have had an email from my friend saying "I think you are right about grandfathers parents, I also think their surname was McRae”. This was before I even mentioned it to him, so well done in spotting that one.
Elizabeth May reg 1900 appears to be the only child registered in the name of Wiltsher, so I wondered if R&A had got married around that time but couldn’t find anything.
I am currently trying to persuade my friend to send for the birth certificate for Edward Thomas (his grandfather) as it is the only way to prove things.
As for finding R&A on the 1891 census, that one remains a mystery which hopefully will be resolved once we have the birth certificate.
Once again many thanks to you all for your help
Regards
sre