I have Cobra Monaco seats that were fixed to the rails when I drag raced the car, the white stickers on the seat rails says about them being for Cobra seats, ill try and get you a picture later when i go to the lock up were they are stored.
They sit low to the floor which i liked as it gives more room and have a good range back on the sliders again good for me as i like my legs straight. Don't know if you have thought of this as your height may make a difference.
I'd take £100.00 for the pair, I've looked for the receipt but cant find it at the moment which is very unlike as I save everything lol
The cost in the region of £125 each when new plus postage etc and they haven't had much use.
You using harnesses with the seats? I've got a nice set for sale if needed :-)
We could meet up easily enough as I'm at side of M1 near Junction 28 so easy to get about and don't mind a run out if it helps.