Like in most cars of the era and even today there are different “grades” of the same model but the name or the suffix letters change with the changes in the grades. Some show different exterior and interiors but some were just interior changes.
Cadillac had the same thing with Sixty Series being the low end and Fleetwood being the high end and DeVille in the middle.
. It can be some things standard on the high could be ordered on the lower models but certain things you could not get on the lower end models. The cost difference usually made it so that you were better off just ordering the high end model vs. a lower model with extras. I remember my Dad ordered a loaded ’69 Crown because he didn’t like the smaller rear window in the LeBaron for safety reasons. As an example I doubt you could order a LeBaron with a Crown back glass or vice versa. Best way to understand what we are saying is just get an old sales catalog for your year and go through it and you will see the many differences in the models.
Since 1999 I have had one 1961 Crown 4 dr Southampton ( aka Hard-Top ), one 1962 Crown 2 dr Southampton ( aka Hard-Top Cpe ), one 1963 Crown 2 dr, two 1963 Le Baron's and an 1966 Le Baron.
At this time I have the 62 2 dr, one 63 Le Baron and the 66 Le Baron.
I "spelled it out" so that you know that I am not just reading off an ad or guessing.
Every era Le Baron was an special order only. There are some interior appointments that are only Le Baron. What is taken as an "norm" on an Le Baron are not that on the lessor vehicle's ( but they are/were an pay to get it item also ).
There is some more, but then ...
Rodger & Gabby