Update on this issue for other V1 users. Instead of trying the 2020-03-28 Buster image, I downloaded the 2019-09-24 image and it worked fine with the Pi3 V1 kit and also the Pi4 V1 kit after building the 2.6 version of the WiringPi. So somewhere between the 2019-09-24 release and the 2020-03-28 release, the V1 Kit compatibility was broken. Just glad I have it running on my Pi4 now.
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