Idea: Make a board where any Agnus type of chip can be used ie OCS/ECS/AGA, same for CPU such that it can use 68000/020/030/040/060, and other periphial chips like Paula etc.
Such that any combination can be used depending on what chips can be found from otherwise "dead" motherboards. So if you find a working AGA on one motherboard, 68000 from a second, and Paula from a third.
Practical design would be multiple PCB pads. And possible configuration with jumpers. Ie use the ones you can populate. So that no scrap motherboard components would be wasted.