Koni did sets for Daihatsu, can find no information for Spax, shocks are interchangeable with other models, though, and certain shocks were only available in other European countries.

It is possible that they were sourced on the internet, and shipped to Britain, or someone picked some up while on holiday.

Interestingly, a friend of mine goes to the States every year for his holidays, and returns with enough spares for his Jeep, and his Harley Davidson; claims the savings made nearly pay for his holiday.