Interesting - do you have any reference source for the gauge conversion of the BNR locos? If this is true, I'm surprised I've not come across it before. The BNR had two narrow gauge systems (actually more, but two mains ones). The largest was the Satpura Lines, which was originally proposed as a 2' gauge line. This would be in about 1897. But by the time the line actually got the go ahead it was January 1902, and definitely a 2'6'' gauge line. It did have tank engines - great big 2-8-4T from Sharp Stewart built in 1901. The other main BNR narrow gauge system was the Raipur Dhamtari Railway. This was originally supposed to be broad gauge, but in April 1896 was sanctioned by the Government of India as a 2'6'' gauge line. Note definitely that gauge - and 1896 correspondence states both this gauge, and the need for four locos. This line is where the four MW 0-6-2 locos of 1898 went, as that line's no's 1-4. As they had outside frames (like the L&B tanks), regaugeing would have required the same amount of work as on the tank locos, so not sure why one was possible and the other not. Nor am I convinced that there is much similarity beyond hat you would expect from contemporary products of the same firm. Why Joy valve gear on the 2-6-2Ts and Walshaerts on the 0-6-2s? Surely the more likely story, unless we have some actual documentation or contemporary remarks on the Indian connection, is that the 2-6-2T were a separate order for the L&B, to their spec? After all, they might not have been the strongest locos or had the best adhesion but they are rather in the style of British and Irish NG locos of the same era, and how many other, much greater, railways ordered locos which turned out to be not quite as good as they might have been?