Another tech question on 85 380 SE.
 

When I finally decided the problem with this engine was the fuel distributor I traded some 240 D parts and got one. Its amazing how fine it runs now.

I had bid on fleabay about the same time and it seems I bought one there for 85 bucks. Now I have two. If both work, is there any special treatment/procedure to preserve the spare?

Use a lubricant that won't attack rubber. Also make sure it's a rust inhibitor as well. Wrap it up tightly in plastic then put it in a ziplock bag. If you maintain the fuel system on a regular basis with clean filters and fuel treatment like bg44k or chevron techron it will probably be fine for the life of the car. The only time I've seen issues with the fuel distributor is when the car has been sitting for awhile.

Thanks.