Looks like your CPU was replaced at one time or another, it does not look like an Apple/Motorola 68K to me (see below). Pins 7 & 8 are the High/Low Data Strobe and Pin 45 is A17.

This looks to be nothing more than a 1MB upgrade (by adding another 512K) somebody tried to add to the board. You need to look for other spots where chips pins were soldered. I say look at the RAM area. One trick was to piggy back RAM Chips and then connect the higher address to the CPU.

If they did that and blew out the old 68K, then they could have replaced the CPU. That is what it looks like in this case, and redid the RAM Upgrade. Then for some reason, removed the upgrade.