Based on the Secretory of the Interior's standards, restoration is bringing an object back, including replacing details and such which were lost...
Repairs or rebuilding an object, i.e. fixing a complete locomotive would probably not be considered restoration. So rebuilding a 3000 class boxcar including residing the car is a repair. Taking a former long RPO car, now a work car for a rotary snow plow back to its Passenger car appearance and function would be restoration. Bringing a body back to its railroad function would be restoration. Rebuilding 315 would be rebuilding or repair.
For those of us on this board the terms are interchangeable. If one were to write a federal or other mainstream preservation grant, and misused the terms the grant would not be funded... They would assume you are unqualified.
Every profession has its own language...
Randy Hees
Society for the Preservation of Carter Railroad Resources
www.spcrr.org