Sorry there won't be much in the way of during photo's for this just afters.
I started of with a thorough vacuuming if the fabrics and a wipe down of the leather with a regularly rinsed MF - I do wish I had a pic of the water after!. I then separated the back from the base and cleaned all the leather with Raceglaze Leather Cleaner. Then using my new Numatic George I wet vacuumed the materials after soaking and pre treating with AG Upholstery cleaner.
Having sat in a pool of water for quite a while the metal tubular seat base/pan was quite corroded in places so I decided to use my original base frame and a new genuine foam base.
Sorry there won't be much in the way of during photo's for this just afters.
A
problem presented itself when re-fitting the cover to the base - there is wire that passes around the bottom seem that is pulled tight to take up material slack and then secured by bending back on itself through holes either side of the metal frame underneath at the back.
Mine had rusted beyond use so I went on the search to find a substitute. I tried garden wire first but it was impossible to feed through the narrow seem! As a cyclist I then hit upon the idea to use stainless steel gear cable which was an exact match in diameter, had the length and threaded/fed easily through the seem (one end comes pre-soldered).
Below!
Rusty original wire
Non rusty original wire
Stainless bike gear cable
The wire was then fixed both sides with an allen bolt and pinching the cable utilising the original securing hole.