What's your opinion on the slack in this 318 timing chain?

I'm tearing into this because of a coolant leak between the timing cover and the block, otherwise I wouldn't be here. I was curious about the condition of the timing chain. This engine was bought from a Chrysler dealer, it came from an authorized rebuilder in Toronto (Ontario Reman) circa 1986 and I might have 10k miles on it at this point.

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Sprocket made in Canada? Links made in Japan?

From what I read, even new timing sets have slack, maybe more than some people want or expect. I didn't measure the slack here, I can, but it looks like 5/16 inch. I haven't driven the car much in the past 2 years (was in storage for 20 years before that) but I'd like to see a smoother idle, don't know if it's the crappy gas now, or my expectations of 550 rpm, or the carb setup, or still having points (not electronic) ignition - or this chain?

I'm going to have to decide in the next couple days if this chain is staying on or if I'm going to replace it. Comments?