My completed trailer ready to camp weighs 6500 lbs. (via scale ticket)
I figure the wood and the rest of my mods added about 1,200 pounds net to the trailer.
If I get to build another I think I might see how 1/8" plywood might work, that would save quite a bit of added weight.
I figure I used about 30 sheets of 1/4" plywood less waste, (counting my cabinets and fixtures) probably about 40 pounds a sheet for birch, a bit more for the oak.
1/2 Ton 4WD Truck, 72 Sovereign