Bill;

Some years ago, successfully replaced the seats of my 66 1800 with headrest seats from a later 1800 (I dont know what year, but it was definately injected, I presume they were o.e., originally supplyed to Volvo by Recaro, the German seatmaker as their logo is on the seatback release knob). Perhaps you can find some of these seats also...check with Don Thibault in Sandwich Mass, or better yet someone closer who is parting out an 1800E. The holes and hardware lined up perfectly, so the upgrade went with little difficulty - no farbication or reinvention of the wheel required - and I highly recommend it for all the reasons you stated. I had the cushions reapolstered with a fiber type material which gives excellent lateral friction. I also replaced the (already at that point)aged rubber band suspension with a homemade metal wire and spring upgrade donated by a decommissioned bedframe...ipd offered a similar kit at one point, I dont believe I saw it in their latest cat...this permanently cured the saggies...and I thought my spine was shrinking!

Regards,