Industrial sofa  

PS
Some thoughts about Arad's Kee Klamp pieces and auctions...
It's always difficult to predict how much things sell for, and in the case of modern design it seems to depend on either how rare or how iconic a piece is. Arad's Rover Chair, made out of Kee Klamp arms, always seems to raise high prices precisely because it is a 'signature' Arad item (and one that was ripped off by Top Gear).
I suspect the thing that might count against this sofa selling is its size. Not many people have the room to display or properly store something this big. But then again, having original upholstery is pretty rare in itself, so this might count for something amongst collectors.
In the end, all you need are two bidders who really want this item. Good luck!

The upholstery can be stored.
Just get the covers dry-cleaned before doing so. Upholstery doesn't "decay quickly" unless maybe the filling is latex foam and you're putting it in a hot attic.
I think the frame is handsome but those cushions are killing me. Their baggy covers don't compliment the frame at all! The first time I looked at it I assumed they were homemade things that someone whipped up because the originals were lost. What's inside them? I wonder if they originally had a better defined shape and the filling simply got compressed with use.

More than happy to defer...
... to your wisdom spanky!
I was thinking more along the lines of mould and mildew as a result of the UK's notoriously damp climate. But if I'm wrong then that's good news.
I agree, the cushions are pretty shocking. But then again, the creative-salvage ethos of early 1980s design in London was quite punkish - it was something of an urban reaction to the twee and 'correct' Laura Ashley aesthetic popular at the time...

Replace but keep
You could have quality leather squab and back cushion made ,maybe with buckles to keep in place.I think it would then look amazing and practical.
Retain original upholstery.
This whole thread has been very interesting and to finally come to a positive conclusion is refreshing.