On my old work boots, I always used a spray on silicone material to waterproof the unpolished leather. It kept the nappy look, yet water would bead on it. It had to be reapplied every few times out in the wet, though. It would also slightly darken the leather - not much, but it was noticeable. The color went from tan to light brown. It actually helped make clean-up easier when they were caked with mud. It's been a while, but I think it was this stuff:
Amazon.com: Sno-Seal Silicone Water Guard Aerosol Spray: Apparel
This appears to be pretty much the same thing:
Atsko Waterproofing Stain Repellent Silicone Spray
Seams on boots and tents were always best combatted by Kenyon's Seam Sealer (now in version 3):
Seam Sealer 3-2 oz. from Campmor
The above stuff got me through 8 years of camping in the boy scouts. I never had a single leak in my tent and my feet were always warm and dry.