I did this project a decade or more ago. At the time, Richard Clark sent me some ashtrays from his inventory for mock-ups and templates. The label size is custom - there is no correct Avery-like label you can buy off the shelf from an office supply store. The font was purchased as it is not included in any Microsoft Office product. Original labels were printed using a flexographic label printing process. While Mr. Clark does have flexographic printing equipment, it was cost prohibitive to invest in a roll of material to produce some 500,000 labels let alone making the flexible plate relief. The custom die to cut a single label to size was $300 at the time. So I made a few correct labels for myself, Mr. Clark, and a few others. Mr. Clark thought my reproduction was too good a quality as the result from a flexo press is done for speed, not accuracy.
The cushion room worked three shifts. Labels were either "DAYSHIFT" or "NIGHTSHIFT."
On the left is an original from Mr. Clark, on the right is my reproduction (aged yellow in direct sunlight for about 8 months)
Below is from GNX 180 - label is upside down, DAYSHIFT
Another example: NIGHTSHIFT
T-topflyer, because you are making an effort to do it right, I can send you one. Just specify DAYSHIFT or NIGHTSHIFT. PM me a mailing address.