Nomenclature question: 146 and Le Grand

[Paul-in-SF]

Are these two terms interchangeable, i.e. they have always referred to exactly the same pens, or are there 146 pens that are not Le Grand (or Le Grand pens that are not 146s)? Maybe the line started out as 146, and at some point added Le Grand because they made it a little bigger? 

 

The bigger question, I suppose, is whether there are resources (online or print) where I could research this sort of thing for myself.

[Karmachanic]

Name/size change.  Didn't stop people from continuing to refer to it as 146 tho'.

https://www.fountainpennetwork.com/forum/topic/352116-montblanc-146-legrand/?do=findComment&comment=4291159

 

I asked the internet 

[Paul-in-SF]

Thank you, apparently I chose my search terms unwisely.