I have a lot of experience of traveling in trains in Bengal right from Durgapur, Burdwan, Kolkata, Maldah, NJP, Darjeeling etc during my posting as RM. I had my office at Bada Bazar and I had a pass of local trains so talking to locals was lot of fun but the only problem was they never accepted wrong Bangla pronunciation. However I always laughed out their Hindi pronunciation We had 5 major distributors in Bengal, 3 in Assam and one each in other NE states.So at times I mixed Bangla with Assamese like Khabe and khabo. I always thought language is just a medium of explanation and nothing else. Enjoyed reading your post.