R.A.B.? Not Regulus Black!!

[Mrs. Hermione Snape]

No: HPFGUIDX 133067

I think the infamous R.A.B. is Borgin, of Borgin and Burkes.  Burke's
first name is Caractacus, given in book 6.  Borgin has been in the
series since  book 2, but has never been given a first name.  He's
always "Mister."  He treats the Malfoys with reverence and fear, but
mutters about them with disgust once they leave his store.  He and
Burke both would have ample knowledge of dark objects.  The locket was
originally sold from their store, and they would have remembered who
bought it, expecting to get it back after she died.

I sincerely doubt that it is Regulus Black.  Sirius said he doubted
that his brother was ever important enough for Voldermort to kill him
himself.  Also, in book 5, R. Black has been dead 15 years.  Sirius
was, at most, 40.  So his younger brother would have been, at MOST, 24
when he died.  Probably younger.  He wouldn't have the experience or
importance to discover the Horcruxes, know how to handle them, or even
to write a well-composed note like that.  Also, wouldn't Harry, Ron,
Hermione, or whoever found the locket have noticed the S for Slytherin
on it?  The description in OOP of the locket they found only said that
it refused to open.  If it is indeed *THE* locket, I'm sure the Blacks
acquired it after R.A.B. (Borgin?) was through with it.

Mrs. Hermione Snape