MK1 sierras there are lots of different ones, MK2 they are all the same but the centre section, the plastic bit is different from model to model on some.
A MK1 panel fitted to a MK2 will be ok until up at the battery end where the MK22 panle sits a LOT further forward, so bonnet will not close on the seal, it will still shut no probs but not seal as seal will be in wrong place.
I made this mistake last year!!
tabetha