How the shares were traded (i.e. which market was used to buy/sell) is irrelevant to your status as a valid shareholder, so I don’t think there is anything stopping you from joining the class action. Probably best to register your details with Banton at the link above and someone there will eventually be in touch to confirm your shareholding etc. at which point you can note your overseas domicile etc. I don’t think there is any restriction on joining just because you bought on the London exchange.
SO4 Price at posting:
31.0¢ Sentiment: None Disclosure: Held