They read OK, although 2 is a little low (and I'd be suss on it for that) on the DC side. (you get about a 0.2V drop between the PSU and the C64 power connector on the 5V line, under load - with no load, you're getting the voltage directly at the PSU.)
10.2V AC is a little high, but I wouldn't be too worried - no chip gets that directly - it's regulated first. It IS the unloaded voltage (and will drop noticeably under any load), and there's nothing you can do about it anyway, it's just what the transformer outputs - Unlike the DC output, it's not likely to suddenly spike to damaging levels.
One of the problems I've observed with C64 PSU's is that they go overvoltage when HOT.. something you really can't test. (aside from one of mine that actually caught fire!!!)
Just sell them "as is" - and with the blanket caution that any old electronic equipment can fail - particularly underengineered, 25+ year old electronic equipment