I can see that the piece pointed out might be turned 180 degrees, but don't see how all the pieces on that side could be, because they would curve inward, rather than outward. And while the pieces you posted in post 198 certainly look correct, I think I see a similar error in sleepyfish's post #196:
View attachment 336299
Unless that group of Right and Left pieces are not meant to go together. AH! I think they do NOT go together as he has posted. The other groups shown have the same numbers on each side (P3L-P8L and P3R-P8R), but the above pic is P16L-P19L and P12R-P15R. sleepyfish probably just posted the wrong pair or didn't mean for them to be "grouped" together.
That still doesn't solve the original problem, as I'm sure there's only one set of planks for the main deck area..