So maybe you could find one (but I doubt it, it's probably a European application)
Some of the well know Lotus shops will install Spal aftermarket fans as an upgrade. You could either go this route or inquire to them if they have a working used Lotus fan to sell. A Lotus parts breaker such as Sports Car World might have a fan as well.
Have you tried repairing the wire? That would be MY "Plan A".