Danno,
I too have seen both items you've mentioned. In the case of the Pillbox, I've only seen it once and i arty'd it before it could do any damage, so i never noticed if it's orientation had any effect on it's LOS.
regarding the trees, I believe they are wood tiles that overlapped with the road. I've played PBEM games in which the trees are smack in the middle of the road during set-up, and then on the shoulder in turn-1.
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The dead know only one thing - it is better to be alive