I used a hydrometer. Didn't use amber caramel (assuming you mean cara amber?), unless the LHBS switched them! Actually, I tasted the malt and it was definitely not a caramel malt. The thermometer gets calibrated every batch by noting that it starts at room temperature and registers 203 F in the boiling wort (I'm at 5000 ft). I've also swirled the carboy several times in the past few days. Also, I added Wyeast nutrient to the boil, so it seems unlikely it would be nutrient deficient.
I'm wondering about the most proven ways to drop a few more points, assuming the fermentation is really stuck for some reason. I've read lots of threads over the years about stuck fermentations, and many recommendations are made regarding how drop a few more points. I haven't seen threads where people report back what worked and what didn't...yeast hulls, pitch dry yeast, pitch an active starter, etc. Any suggestions what works best?
I have had success with unsticking a fermentation by racking the beer onto a recently flocculated yeast cake, but I don't have one handy at this point.