Think it may have been built by these guys:
http://www.rk-engineering.co.uk/
Saw it advertised previously and came to that assumption as I have family in st Agnes and they sorted my partner's Lupo out when she broke down on her way to Cornwall once.
They're a good set of guys who know what they're doing. If they did do the conversion I'd be surprised if it's not done right.
Give them a call and ask if they know the car perhaps?