I did what others did, after fruitlessly searching for wiper blades (here in the US) that had the "insertion pin" attached. I bought one shorter blade from NAPA that had a pin insert (note: there are different sizes of these "pins" listed on various wiper blade packages) and used that for the pin, and then bought a 24" wiper blade and used that. I regret I forget what size I chose, but it is a bit long/loose and thus will also need a tiny plastic or rubber washer to tighten up the wiper blade so it does not "jiggle".
Unfortunately, I realized too late** that the Lotus wiper blade seems to be like my '72 Grand Prix's blades: you don't actually change out the entire assembly, but instead you merely purchase the rubber strips that wipe the glass and remove old/install new (which is a similar operation as the Grand Prix blades don't come off the glass more than maybe two inches, unlike modern cars where the blades can be set to near-vertical).
Cheers,
Scott
**meaning I stupidly threw away the entire Lotus blade assembly. DOH!