I never known the leon to have leather heated seats, it was a option that was rarely fitted. If you got the leon heated seats then you can get the looms and switches from tps or seat md. The electric seats need an earth and a live feed the earth feed you can get from the bottom of the hand brake and the live from the cig lighter. You will also need a conector loom you can prob get them from breakers. If there from a golf-bora/a3/octavia you can use the looms for electric and heated but you will need to modify the airbag loom to fit. I did have a diagram somewher and when i find ill send over. Its not a hard job you just need patients and the center consol will need to be removed and wiring under the carpets.
Thanks for a great reply. Very helpful.
I think the leather seats were fitted to a
Cupra R. They are beautifully made, much better than those in the VW Golf which would of course have been another option.
On the loom, I have drawn a blank with breakers. The breaker I got the seats from had disposed of the car by the time he advertised the seats, but I found an eBay seller who makes new looms to order. I bought one of those and a pair of used switches so I'm good to go.
The car has only done 34,000 miles from new and is in excellent condition. I intend to keep it for a few years and use it on weekend trips of about 250-300 miles so the leather seats will be a good enhancement to comfort.