Front Turn signals are inboard on the 67 (more on the corners of the 68) and no, they don't have the Rear side marker the 68 has. The Interior of the 67's have the upper section painted, (which I personally like much better) The console (if so equipped) on a 67 is the Camera grain and has a rear ashtray and a rear light, and the shifter for an AT uses a dual plate set up with the chrome trim accent. The speedo/gauges are a slightly different color tone than the 68. Earlier 67's had the mono rear springs, but usually had one radius rod or for the more potent combo's they had two radius rods (Traction bars) (late in the 67 model year they were changing over to the multi-leaf springs) The center dash wood grain was horizontal, (changed to a Burl wood style in 68) The dash pad is slightly different, more straight forward.
There were actually quite a few little things that are unique to the 67 that make it all it's own, and in many ways something a little different from the crowd, especially the Camaro crowd. The 67 Camaro's were pretty sparse and void of character as compared to the Firebird which was well appointed standard, not just by adding options.
Common rust areas that can come up) Right around the rear wheel well openings, inside the trunk on either side debris collects down in the crevice between the trunk floor drop off and the fender, moisture gets in there and causes a typical rust area. Lower rear area of the front fenders, trunk pan, Front floor pans, lip where the front corner extensions meet the fenders, rocker panels from the front wheel wells back, Below the rear windows if it's not a vert etc... look closely for previous body repairs inside all fenders (look for patched areas)
If it checks out, I say Go for it, you won't regret it! It's a bird after all!