When I started collecting Texas Instruments programmable calculators I was amazed at the variety of bags, cases, pouches, boxes that came with these calculators.
For the same calculator, the accompanying case was not the same depending on the country or the year of marketing.
The "Slanted" models seemed to have, in all countries and for all models, the same hard plastic box with hinges, only the color varying from one calculator to another.
Then I found exeptions, a TI-55 II, a BA-55 then a BA-54 that came with soft plastic sleeves.
You could compare here with your own calculators.

Then from the 90s appeared the hard plastic covers in which the calculators slipped. (TI-68, TI-60X, TI-67 then graphics)...

(Several HP calculators entered this collection : Hewlett-Packard's NON-RPN programmable calculators ! [plus a few RPNs...])