Phone some of the lime retailers - they can probably put you in touch with someone that may be able to help, and they're always willing to chat if you're planning to DIY.
The periodproperty.co.uk forum might also help.
I've tried Ty Mawr and Welsh lime, most of the numbers they gave me were for defunct companies. Thanks for the forum link though.
@Polygon started
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Phone some of the lime retailers - they can probably put you in touch with someone that may be able to help, and they're always willing to chat if you're planning to DIY.
The periodproperty.co.uk forum might also help.