I won't bet the farm on it, but I'm nearly certain my '88 Burb was single stage (It had been resprayed in base/clear and the clear is wearing thin). My old '90 Burb was original paint and it was base/clear.
At any rate, the OP's rig is NOT wearing it's original paint and the clearcoat delam is likely a cause of low quality paint or improper prep. Much like these two re-sprays lol:
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For what it's worth, the rig in question is glossy overall. I personally would just drive it ant not worry about it.