How to decrypt/decipher/view old chats, from the "MsgStore.Bak" backups?

Greetings.

I have a very old Nokia E5 phone, on which I used Whatsapp years ago.

I want to retrieve some old chat/messages from there.

Being Symbian, there are no backup databases, or some such. The only available backups are these 3 files :

MsgStore.bak.1
MsgStore.bak.2
MsgStore.bak.3

I copied these files from my old phone, onto my laptop

But, I cannot open/view them. I have tried everything --- Whatsapp viewer, Notepad, Wordpad, etc

I even tried renaming the file extensions. No luck!

I searched online for a solution. Unfortunately, there aren't any. All whatsapp-related issues seem to deal with Android phones. No solution on how to deal with backup files from old Nokia phones.

Even Whatsapp viewer can only handle actual database files (with the .db extensions). Nothing to view the .bak files

I would really appreciate any help/tips

Thanks