storing leather seats

[Lee Levitt]

I found a complete sport leather interior for my '99 A6 and so now 
I need to store the stock seats (front and rear). I expect at some 
point to want to put the stock seats back into the car, so I'm 
going to keep them.

I'm not sure the best way to store them long term...it could be 
several years before they see light of day again. The front seats 
also have airbags. They're black and the leather is in very good 
condition.

Ideally, I'd store them in my attic, as I have the most usable 
dead storage space there. But it gets hot there in the summer, 
perhaps as high as 130 degrees and cold in the winter (below 
freezing, perhaps to 20 degrees).

Is this a safe place to store the seats or should I make some 
space in a more climate controlled area?

Either way, what else should I do to prepare them for storage? 
Treat them with leather preservative, wrap them in plastic and 
seal? Put mothballs in? I don't typically have rodent issues, but 
I'd hate to find them all chewed up 3 years from now.

Unfortunately, they're not worth very much on the open market, or 
I'd just sell them. But pairs of front seats sit on ebay for 
$200...

Thoughts appreciated.

Lee
'99 A6 quattro avant 135K
'96 A6 quattro avant 120K
'95 A6 quattro avant 150K (for sale)