Grant Stockly contacted Optima (Elma) for duplication of the case in 2006/2007 for his Altair Kit project.
His notes, in developing that kit (photos on link):
Another important part of the Altair Kit is the enclosure! The Altair wouldn't be an Altair without the Optima case!
As many of you know, the Optima case was discontinued around 20 years ago! This is a problem!
I contacted Optima and paid them to reproduce the case for me as a custom part.
So it is in every way an authentic Optima enclosure. Employees who manufactured these cases still work for Optima and remembered a lot of the details about the case and its construction.
The case is made by hand with the assistance of CNC (computer numeric control) machinery.
The paint/color codes used on the cases is identical to the cases sold in 1975.
The front panels are powder coated and then silkscreened with white ink.
The silkscreening method used on these cases is more durable than the method used in 1975.