How often to change synthetic tranny fluid?

I just bought a 1972 250C last week. The previous owner never let it sit for long periods of time, but he only put about 100 miles/month on it. This means that that the tranny fluid is three years old, but
only has 3,000 miles on it. Looking at the service receipts, The shop used Redline synthetic transmission fluid for the fill.
I've got two questions. First, the owner's manual recommends a 30,000 mile change interval for the tranny fluid. Would this be extended at all since there's synthetic fluid in the tranny now?
Also, Is three years "too old" for synthetic tranny fluid that only has 3,000 miles on it? The fluid still looks bright and clean, smells fine, and the car's driving great.
I'm trying to decide whether to change it now based on the age, wait 27,000 more miles and change it based on mileage, or split the difference and change it in 10-15,000 more miles.
Thanks, Scott Gardner
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Scott Gardner

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I would leave it alone for another year.
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