I recently picked up a Kestrel SCi frame/fork, with a few other bits. Mine's white. I looked online to see if I could tell the year of manufacture from the serial number or other info, and found nothing helpful. Apparently these frames looked very similar from year to year. I know that they were originally made in the US, and then in Japan. Below the headbadge on mine is says 'Made in Japan' so I know it's a slightly later one, but I couldn't even find the exact years they were made in either the US or Japan.

I'm not sure changing the crankset is going to get you much. The Shimano 600 Tricolor stuff is quite good, especially for the money. Your chainrings look to have some wear, but they don't appear critical just yet. I have read some reports that the Mavic Reflex rims are weak and damage prone, but that's second hand and anecdotal.

The paint on these things is VERY thick, and prone to chipping. This apparently doesn't affect the structural integrity. That's probably the gouge you're seeing. Overall your frame/fork looks in vastly better shape than what I bought, and your components look just fine. I'd adjust it, lube it, and ride it. For comfort/fit, I find messing with saddle (both position and type) and handlebars (both position and width) are more important than subtle frame geometry differences. Also, I'm not a fan of that stem, but if it works for you, use it.

Can you do me a favor? If you pull your seat post out of the frame, can you shine a light down there and tell me what you see? The seatpost is stuck in the frame on mine, and I'm patiently putting PB Blaster and ATF/Acetone in there, but I'm not sure if it's open from below. If you shine a light in there, can you see down to the bottom bracket? Thanks!