Conservation -

Leave the bike alone (in its existing condition) except for light cleaning, oil,...maintenance. Retains the "patina" that comes with age. Arrests any ongoing corrosion or other damage mechanisms at play.

Restoration -

Return the bike to its original condition. Usually means the bike is too far gone for conservation or the owner wants something more than a pure conservation offers. May be a minor or major overhaul. Minor being replacement of parts with original equipment. Major being new paint, new seat, etc (all of factory specs) plus everything/anything that is likely to be in the category of "minor".

Reproduction -

A newly made unit that looks identical (or nearly so) to an older unit. Some reproductions cross the line into deliberate forgeries. Some are nearly so but with an intentional identifying mark on them (i.e., a different serial number) that proves they are just a reproduction. Some are updated versions based on the older design.

I think we are very close in our understanding of these terms.