Hi
1) Looks like a Renault 5 Mk1 silencer/muffler for the 800 engine (R1221). The Renault part number is 77 00 584 051 in early parts books (no silencer to manifold clamp). The larger engined 5s (689/688/some 810s) had a silencer with a captive clamp; later parts books just have one number for all these engines: 77 01 366 355.
2) Looks like the silencer for the 688/C1E engines (some R1128s and for the F6 van, etc.). = 77 00 578 691.
3) Looks like the silencer for the smaller-engined R4s - (R1123/2106/1120/1126, etc). = 77 00 647 095.
Hope this helps!