The DHR is 610mm, Gwalior (Scindia State RY) is still 610mm, USA 2' was all was 610mm.

I do think the new WHR is 600mm though, and the SAR RR's were 600, and they had and have big thick flanges, which if cleaned up to normal size would make that gauge about 610mm. If my equipment ran on those tracks I would probably have to change tires anyway.

I would happily go with 600mm on the equipment, but it might not work with the "back to Back" dim. used on my 24" gauged track. The back to back is critical to the "check gauge" and Frog designs.