As it looks like you figured out from you signature, your floorplan is a 40RH. It's not listed in the 2003 brochure (only shows up as of 2004) but it's quite common as a 2003 (we have the same).
It does happen that chassis / models are different years but it's also very common that the brochures are not up to date or changed during the production year (around that time, they also change the rear closet to include drawers and moved the rear slide window to 1 window on each side of the slide. Options also changed).
If you want to know for sure, check the information page in the rear closet or contact Tiffin with your VIN. Ours states 2003 40RH from 02/14/2003.
One issue to check with those models is the 'wet bay' problem. Unfortunately ours does have it and so far Tiffin will not help with the repair costs (They will fix 2004 and newer at no cost but said it doesn't affect 2003s and is not covered).
If you want to see the 2004 brochure, it's available at Tiffin RV Network