Got the belt and pulleys replaced. 51 teeth took a bit of effort to attain but with the tensioner fully retracted, the belt went right on. Trimmed the crank "opening" as suggested.
Although the "old" belt had been replaced about 45K miles ago, it was also 18 years ago!! The new belt is clearly more pliable, particularly the teeth. The upper surface on the old (Honda OEM) belt was ok compared to the teeth. No cracks or anything like that. As I was putting it back together, I mused about the gaskets on the belt and pulley covers. Are these typically replaced or perhaps a smear of silicone gasket? They don't seem to protrude much beyond the surface. It looks like the PO had the thin layer of silicone gasket.
Thanks for all the valuable input. I appreciate your time.
Mark