tenex
reality-based
I don't know why the rubber on some of these binos has such issues, unless perhaps subjected to high heat? We had both the 7x50 and 15x60 in our family (1980s T* vintage), the latter for three decades, and never had discoloration or cracking. It stayed quite nice and flexible.
Steve, you've said nothing about the glass surfaces and internals, which will matter more to value than the cosmetic condition of the rubber bits. But it's such a lovely (and rare) thing I'd be tempted to keep it. Do you like it yourself? Some people prefer 7x and this was my father's model of choice, which he carried around in our mountains and other areas of the western US. Individual focus is not for birders (nor is this weight), but for other purposes, at 7x you can find a setting that works and just leave it.
Steve, you've said nothing about the glass surfaces and internals, which will matter more to value than the cosmetic condition of the rubber bits. But it's such a lovely (and rare) thing I'd be tempted to keep it. Do you like it yourself? Some people prefer 7x and this was my father's model of choice, which he carried around in our mountains and other areas of the western US. Individual focus is not for birders (nor is this weight), but for other purposes, at 7x you can find a setting that works and just leave it.