Further to this one:

In a box of components that I am putting on eBay, I came across a small AIO logic board with a 68030 marked 16MHz, and assumed it was a Color Classic. I took it out to pop in a Color Classic for testing, got my two 30-pin SIMMs out, and proceeding to put them in ... discovered that it took a 72-pin SIMM. It was from an LC5xx machine.

For obvious reasons, I fired it up, and discovered that it runs at 25MHz. It is not an exact match for my other LC520 logic board (presently being auctioned, and which is marked as having a 25MHz chip), but it runs at the faster speed and works perfectly in the Color Classic (which thinks it's a Color Classic II in the diagnostics software used to test the components, despite its running at 25 rather than 33 MHz). I confirmed the speed with Gauge Pro, Apple Personal Diagnistics and MacCheck.

Thinking this was rather interesting, I then compared the chip markings on the two logic boards tested, and discovered this:

Color Classic @ 16MHz:

MC 68030FE16B

04D66C

QEWD9325

MALAYSIA

LC5xx @ 25MHz:

MC68030FE16B

04D66C

QEWV9250

MALAYSIA

Assuming the last line is a date code or something, they're surely the same.