Never seen Stronglight oval rings yet, but these manufacturers sometimes make some things for a short time and quit maybe because of patent infringement problems that pop up? It could be just like the Selle Italia Daytona Saddle that I recently aquired that looks like a very close copy of Selle San Marco's Regal saddle.

I don't think the Selle Italia version was around too long because I never seen or heard of them before I got mine recently. Interesting thing about the 390 cranks featured in the pics you linked is the pedal holes seem to have not been bored at the center of the crank arm end lobes. Could they have been trying to save money and just forged one legnth cranks and just adjusted the distance of the holes at the ends to come up with different crank legnth sizes?? Looks kinda goofy.....
Please post up some picks as soon as you get it!

Chombi