where can I buy a spare spring for my McCulloch Cambrai 321 strimmer?

Please where may I buy a spring (for the line cutter head) for my strimmer. I live in France and so need to buy something on the net/mail order. (A mouse chewed the plastic bag where I keep the strimmer spares and the spring fell out I know not where :-/)

The strimmer details are
Model Cambrio 321 Type BC 010 B ML 03. PNC: 953900342
serial number: 50302205
ML 03
Year: 2005
I am not sure where it is a 34 or a 38cc model.

Thanking you in advance
Minkie Best