In the end I decided on a fix that did not involve the complication of dismantling the whole seat base. Due to the way the leather is fastened to the frame and stapled to some pieces of wood, which are riveted to the frame, I decided that that would be too specialised for me.

I purchased a pack of 8 25mm luggage straps that are 1 metre long from Amazon. They have metal buckles that grip the strap. I was able to get the straps under the wire on each side and under the original "spring mat" then back across the top to the buckles. In the end I only used 6.

Because of the seat structure the strap nearest the seat back was impossibile to get closer to the back on one side (left of the photo below) and I did not worry about trying to get an extra strap towards the front of the seat (right of the photo) because it is supported by the metal plate.

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Having tightened up the straps I cut off the excess and tucked the tails back under the straps. The buckles are under the straps and under the seat so you do not feel them. I never try to stow anything under the seats so that is not a problem.

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The result seems to be as comfortable as the original so it will probably stay like that for a while.

I sprayed a little silicon on the rails to try to improve the ease of moving the seat fore and aft but it did not help a lot. I was carefull not to overtighten the anchoring bolts but in the end I came to the conclusion that the left to right distance between the rear holes had been drilled inaccurately so that the tracks are not completely parallel. I measured it as best I could and the back seemed to be about 1mm narrower than the front. The seat slides easily when it is forward but tightens right up when it is towards the back. I do not think that the cause, in my case, is the nuts under the middle of the rails. In any case the next time I have the seat out I will change the guilty bolt to something better.

Peter

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