ross/curtis 027 track?

I bought a couple boxes of gargrave track and it had some sectional ross/curtis curves in it. I thought some of them were 0-31 curves but I purchased a box of gargraves 0-32 and the stuff i have sits inside of the gg with room all the way around. I measure 32" from inside rail to inside rail on the new gg and 27" on the ross/curtis. These are definitely factory sectional track and not felexible, they have the spanners between the ties and they have the pins to hold down the rail in each tie. Does anyone know if they normally made 27" dia track or did somebody modify it?

Also, how do you tell the difference between straight sections of gargraves rigid and flexible track?

Thanks