Well that 1,689# OCCC isn't a heck of a lot, considering your full water tank takes over 300# of that capacity.
Not that it matters or helps you, but my 32 1/2' class C on an E450 has an OCCC of 3,275#. With my wife and I on board with a 3/4 tank of fuel and water tank about 1/3 full the MH weighed 11,940#.
It looks like your MH weighs about 2,000# more than mine. I'm sure it is and looks nice, but as you've found, you pay the penalty in the extra weight of all the extras.
You can stay under that OCCC figure, but it can be difficult. Taking my MH as an example, the weight of mine after deducting the full fuel in the OCCC figure is 10,895# for the vehicle when it left the factory. If we had full water,fuel along with everything else on board, we would have been 12,270# or 1,375# more than the base vehicle weight. We also have a fair amount of extra "stuff" we carry around, because I've been too lazy to get rid of it.