Click on the "search" at top, then type in Bighorn... and you will find many topics to keep you busy.
As for curved beds, I believe you are correct. Many folks, myself included, like the older Bighorn. Fred loved his early 70's Super Kodiak and almost copied it when he began the company.
Value depends mainly on what a buyer is willing to pay, but I say one in excellent condtion in popular weight (45-55#) may sell $350-450 and maybe another $150-200 for spare limbs.