original HP calculator cases.

[burkhard]

Here's a picture of what I am talking about with respect to the two different designs of HP-41 cases I have. I lined them up such that you should be able to see how the "little" case is both a smidge shorter and a smidge narrower than the two "big" cases.

And the color is a bit different—a greenish cast on the "little" one, which isn't too appealing.

My guess is that the little greenish case was the earlier design, but fit was too tight (especially with the cardreader attached) and the color had taken some complaints, so they tweaked each a little "at some point" during production.

I just don't know when (or with which variant) "at some point" took place. Any ideas?