i just ordered a OE set from SJ Motorsport . At first they told me only aftermarket gaskets were available , then I got an email from Steve a couple days later saying Lotus still had a few left. Part # A918E0029F, they were 600.00 GB. About $900.US. I placed the order, haven't received them yet.
Mitch, just got contacted privately by another forum member who mentioned he had an issue with the JAE supplied head gaskets as well. We assume now we got aftermarket ones from JAE last winter as we are having identical issues to the other car. He also solved the issues with OEM gaskets.
I cannot source the OEM gaskets locally as our dealer does not stock or source any parts for the older cars. If you get a lead on a gasket set for sure let me know.
I actually recovered two pieces about 1/4" diameter of what looks like head gasket material from the coolant header bottle.
Real pain. May have to re do the head gaskets.