London Office address for RPRF draft submission

[ADBoy]

Dear All,
I have received my medical exam and RPRF letter. My visa office is London.
They said in the letter that a reply label is enclosed. I am unable to find it.
Can any one, who has submitted the RPRF draft to Londin visa office, advise me to which address I have to send the draft.
Either to

Canadian High Commission
38 Grosvenor Street
London W1K 4AA
UK
(Address written on the letter)

or to

Canadian High Commission
1 Grosvenor Street
London W1K 4AB
UK
(Return address on the envelope)

Thanks