For me it's not a question of Restoration vs Preservation for this specific poll/thread.
I think it's more a question of cleaning up the bike, removing it's hard won road grime
and oxidation (i.e. see the Zeus hub that another poster found). For me again cleaning
up is part of the preservation.
If we are talking paint here, thats a completely different story and I usually opt for preserve
the original finish.
To quote myself (quoting someone else) "It's only original once", but it can be clean
many times and still be original..
good thread.

marty