Make your own Planck 6502 board
To create your own Planck 6502 expansion board, you can use the provided expansion board template (see Design files above)
This Kicad project provides a base schematic and board layout for you start designing your own board.
Of course, you can also create an extension card using some prototype board and a 2x25 pins right angle header. Actually I would strongly recommend you do that before having your PCB fabricated.
Alternatively, you could also get a few prototype boards fabricated to be able to create many boards or refine designs to your heart’s content.
For example, here is the prototype of the OPL2 board