1.Evaporator can be replaced,you just have to remove the complete dash to do it.(Also ,R+R Vacuum Pods when you're in there.)
2.Timing Chain Wear (Which for some reason we still insist on calling "Stretch")
can be measured and a new chain Rolled in.(Check Sprockets and guides at the same time.)
GSXR'S pre-purchase list for all W124 s.
(Nice inclusion of comments by Marshall Booth,)
http://www.w124performance.com/images/W124_stuff/124.1x3_buying_tips.txt