One of the rules for building a model railroad (if you're trying to model specific locations) is to keep maintain geographic accuracy. If people know the location you're modeling, then shuffling towns ("first the train goes to San Francisco, then Los Angeles, then finishes in Sacramento!"), building a town in its mirror image, or making the mountains climb the wrong way will only confuse visitors and folks running trains on the layout.
You can't always help it, though. On my layout, I assumed the tracks out of Los Gatos stayed on the west side of Los Gatos Creek til past Alma. Unfortunately, when I started modeling Alma, that meant that if left was toward Los Gatos and right was towards Santa Cruz, then I should be looking down the hill when looking into the scene, and the station should be on the far side of the tracks. I couldn't make that work both for space reasons and making the scene easy to view. The scene was flipped front-to-back, but I couldn't do much about it. I just assumed it wasn't too noticeable, and moved on.
Luckily, I was looking at old photos today and getting confused about the arrangement. Where was Alma? Where were the railroad tracks in relation to the old road? I'd look at photos like this one and think "ok, I'm on the west side of the canyon on Highway 17, looking east across the canyon, and there's the creek, and the road must be somewhere between me and town." Then I'd see pictures of the gas station at Alma which looked like it was in the bottom of the canyon. Where was Alma?
Luckily, I finally double-checked. The USGS now has old topographical maps on line (huzzah!), and I found the attached 1915 snippet for the area around Alma. It turns out I was completely backwards; Alma was on the east side of the creek, and the panorama is looking towards Los Gatos, not Santa Cruz. The road crosses the river twice, and the gas station was on the floor of the canyon. That road crossing wasn't just an access road; it was probably the state highway to Santa Cruz! Best of all, my Alma scene was arranged correctly, where looking left leads to San Jose, right to Santa Cruz, and straight ahead leads to the ridge with Mount Umunhum. My scene is correct!
It's an awfully minor detail, but it's fun knowing that the scene worked out right in the end!