I saw my bicycle chain very dirty so after many months since last time I cleaned it and I checked the general state of the drivetrain. I totally forgot that a couple of years ago the chain was already somewhat stretched.
I found what looks like a very worn out chainring, a very stretched chain and a cassette in a mixed state.
Chain is 1.8% elongated.
Cassette: it looks like the 2nd sprocket is the most worn out, the 1st, 3rd and 4th not so much. It is a Maillard Helicomatic so I cannot easily find new sprockets, and probably not new in any case. I may need to replace the whole wheel. I wonder when this bicycle has been manufactured...
Which parts is good idea to replace now, given the actual status?