disco 1 seat subframes

i am going to be buying half leather for the disco but have been told there is 2 diffrent types of runners on them...how can you tell,is there a notacable diffrence with them,mine apears to be two flat runners sitting up on a cubby hole if that makes sense.
dont want to spend money on something thats no use..

What year Disco is it? The seat subframes changed between MY1995 & 1996.

its a 98 all sorted now fitted okay seats were out a 96 es.