the barrel plug i used can be purchased on aliexpress at the link below, but i believe most generic 12-24v plugs should work.

10pcs 12v Dc Power Plug Male Jack Connector | 2.1x5.5mm Dc Power Jack Connector Male Female - Connectors - Aliexpress

The specific magnets I used can be purchased below. The magnets can be pressed in pretty tight, but glue can be used for extra security.

Amazon.com: DIYMAG 200PCS Refrigerator Magnets Premium Brushed Nickel Fridge, Office Magnets, Silver, 6X3 mm : Home & Kitchen

I pre-wire a 2 inch or so pigtail between the plug and controller, then press fit the plug into the case (will be very tight), then put the controller in place into the case and press the back on the case and the LEDs can be wired in from outside.

The text/logo can be painted in Bambu Studio with the fill tool, but will print flush.

LED controller can be purchased from Dutch Developer at:

BL LED Controller - Etsy

Installation/Configuration instructions can be found at:

BLLED Controller (dutchdevelop.com)