Agree with Wes and Mark. A restoration. Not modified, not 100% original. Replacement parts should be NOS or used OEM period correct originals. Reproduction parts should be disclosed.
Agree with all the above. I believe in disclosing any changes even if period specific. Any of my drums that I have, if a part is missing or needs to be replaced is always done with OEM parts from the same period and I log any changes made in a spread sheet I keep for my collection. I would personally never modify a drum and try to sell it as original without disclosing the changes and will hunt for a few years to find the replacement part before going to aftermarket or a replacement part that is non OEM. Just my 2 cents.