Conservation has little meaning to me, besides saving water, minerals, and fossil fuels for my use.
Needed Repairs/Maintenance is getting the bike to work properly as is, including wear-out replacements.
Restoration is spending way more than value added to get the vehicle back to original specs.
Reproduction is a copy of an original, with accuracy only a guage. monodo's EM, EddyR's 7-11...
Rehabilitation is to correct flaws to normalcy, and that's what a flipper may do, and varies by degree.
Tuneup and Upgrade is what I pretty much do. I do the needed repairs, maintenance, and upgrade to compete with a newer market.

Around here, everyone uses "restore" as a broad term that can encompass all of the above. I know what they mean.