Help me understand 84 vs 85 Westy panels

[Nick83]

I've got an '84 GL to which the Westy camper equipment was added. All of my panels are just plywood screwed to the frame. I'm looking to replace them all with new panels from Sewfine, but '84 seems to have been a transition year...

My understanding is that '84 Westy's had panels which used a rail, while the '84 GL's used clips. I'm pretty sure I can just order the 85+ style panels for the majority of the van. The only difference I can find is I'd need an '84 style slider door panel:

The drivers-side (behind the cabinet) panels are a little more confusing. I don't see any mention of 85+ style Westy panels at Sewfine, just the 80-84 panels:

I'm not sure if the difference in the shapes of the panels has more to do with the model year or the cabinets. Why do the L shaped panels have a notch, where the 85+ panels are triangular? Also, I don't have all of the standard bells and whistles in my van, so I'm unsure what all the templated holes are for. Are my guesses correct?