0.2 layer height recommended for nicer fitment and joins

25% infill

Supports needed for both bottom parts at the join

Bridging mode recommended for tops for nicer squares (Cura)

0.1 mm tolerance for bottom to top
0.15mm tolerance for joins

Magnet pocket 5.3mm x 0.9mm but not needed, I used the following
https://www.ebay.com.au/itm/133325623764?var=432730831536