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It is apparently compatible. Lotus Garage has the parts available. British Racing Group has as well. I inquired about the hard tops (they have several options avalilable that are compatible with the Roadster. The Elise soft top should fit - search this forum for 'soft top elise' and you'll find references.
I bought a new soft top from Tesla a few months ago after looking at Lotus Garage and others. As I recall, Tesla's price was just slightly under the others, and the part was in stock. Just about $1K.