does anyone know if ami-6 chairs have a narrower frame than ami-8 chairs? I don't mean the rails. I got some ami-8 chairs for in my 2cv, but the frame is fighting with the seatbelt roll...

If I recall try swaping the seat belt roll to the rear and the static end to the front. this should provide space to fit the seats in. i did this when i fitted bx seats to my dyane and it worked so you should be able to fit ami seats as well

I found out that the seats I have are lower than the original, I couldn't see over my spare wheel at the bonnet anymore. I am going to look for other chairs (early ami-8 or late ami-6)