David
Unless your gear lever feels like it is swimming in a bowl of porage it is probably not the linkage.
My experience is of Talbot gearbox problems is based on Bagheeras, Ranchos and Horizons rather than the 2.2 murena which has a Citroen box but the clutch works in the same way. It is a hydraulic clutch, as opposed to a cable, with a small master cylinder directly connected to the pedal and a slave cylinder at the gearbox end.
A sure sign that the system is not working properly is a very low biting point. This usually means that there is air in the system and the most common culprit is the slave cylinder. For Bagheeras etc with the 4-speed box (and the early 5-speed one fitted to some Talbots) this could help destroy the syncromesh resulting in a good crunch when engaging gears - especially second gear (not sure why this one is usually the first to go).
Depending on how easy it is to get at on the murena, the slave cylinder can sometimes be repaired by being stripped down and cleaned up with 800 - 1200 wet and dry paper. It all depends on how much corrosion is there.
I have no idea what the availability of seals kits or replacement cylinders are. There is a Simca one on fleabay but you would need to check the part numbers.
http://cgi.ebay.co.uk/SIMCA-1301-CLUTCH-MASTER-CYLINDER_W0QQitemZ120118030432QQihZ002QQcategoryZ9903QQrdZ1QQcmdZViewItem Perhaps someone else can advise.
Another possible problem could be a fault release bearing but this is usually accompanied by a lot of noise wheh you press the pedal.
Good luck.
David