Do you mean the chapter ring? You may want to have a word with Christian in the post below as it looks as though someone has placed one or something similar on a 2446 he's considering buying!!

A couple were advertised on here a few months back. Perhaps being sold by Paulo or Amer. I don't recall who exactly. Suggest you do a search. From memory it / they were advertised for around £150

Hi all,
: Does anyone could tell me how much cost an inner lunette ring in
: good condition? And how difficult to find is it?
: Thx for your help
: Antoine