Ian,
That should make life a little easier – presumably 185×400 as you are in the 6 cylinder section of the forum.
I can’t help you myself at the moment but if you are still looking next summer I can almost certainly pick some up from one of my French friends.
Meanwhile, have you tried Bryn Hughes? He has an ad in the classifieds in recent issues of FP and I know he has some interesting stuff.
Keep us posted.
B…