Jim,
Your resistive-type bass traps made from OC703 work best when placed out from the wall a distance equal to 25% of the offending wavelength. So, for 100, 80, and 63Hz peaks, you should experiment with an air space of 33.9", 42.4", and 53.8" respectively. Obviously this really intrudes into the room physically and visualy but it wouldn't hurt to try a little experimentation.
Try placing the traps in the 4 room corners with the air spaces as indicated above. Try a bass trap in the middle of the front and rear walls, again with the same air spaces. I found the front/rear wall absorption seemed more effective than side wall absorption for bass but that could just be my room.
If you can't tinker your way to sonic bliss with the bass traps then you'll need a parametric EQ to tame the peaks.
For what it's worth, my room dimensions are multiples of one another (a bad thing indeed) which compounded my 80Hz peak making it a 19dB peak. I reduced the 19dB peak to 2.5dB by using very thick (i.e. 27" thick including an 8" air space) bass traps of OC701 in the four room corners and some in the middle of the front and back walls. (See my System for pictures of the DIY bass traps that double as Mid/High frequency hemi-cylindrical diffusers, for what it's worth.)
You can also use 2 or 4 subwoofers to constructively reduce the peaks but is much more complicated.
Good luck and be sure to let us know how it turns out.