OCI postal - How many copies and which original documents

[physku]

1.) Can anyone please help me understand how many copies of support documents (british passport, naturalization certificate, surrender certificate, and possibly cancelled indian passport) I should send. My understanding is just one self attested copy of all requested. My understanding is also that if I am sending copy of surrender certificate, I dont need to send copy of cancelled indian passport. The surrender certificate is proof of having had indian pp before.

2.) Also should be I sending original of naturalization and cancelled indian passport. My understanding is just original of surrender certificate.

3.) Is it just one special delivery return envelope. Someone was suggesting that I should send a first class envelope for acknowledgement (why should I if I am sending documents to consulate by special delivery which i can anyways track).