I went through this exercise a few years ago.
I got a replacement from Lifestyle Renault for both the front and rear windscreens. It wasn't chrome in colour though, it was black. It looks good and it doesn't get that horrible ingress of green mould. It fitted straight in, no messing (with the right tools).
I also got some good samples that were a very good match to the original (and chrome) form classic car trim suppliers.
Edgware Motor Rubber and Woolies Trim spring to mind.
Cheers.