I am a new member but have been lurking for about 6 months so.....at the risk of being kicked out, I have a tire question. I purchased a new to me 2009 31 foot Keystone Hornet TT in September 2013...
The only issue I find is a load range "D" tire on an 8500lb dry TT! my trailer is 7100lbs dry and and I am running load range "E". your 8500lb dry is going to be at least 10k lbs ready to travel! I`de be more worried about the tires being being to small for the trailer (load rating).
I would replace them! I go about 5 years on a set of tires for the trailer. my Carlisles have at least 10k miles on them, with most of those in 90 degree temps!