Doesn't explain Mercier/Amersham Road, though. That showed its former
name into the 1950s.

it is not given to many of us to be perfect: neither I nor those sites
claimed to have every change.

You did not indicate when you were young - ie the earliest you know that
the name was Mercier. Other things being equal the change might have
taken place during the war; or have been missed by Rayment. I
can tell you that it was Mercier by 1945 but nothing off the cuff beyond
that.

We do carry out paid research on occasion though, so if you really want
to know PM me and I'll quote you a no-find no-fee price.
--
Robin
PM may be sent to rbw0{at}hotmail{dot}com