The MiniPCB Version 2

The image below shows an OnStep built on a MiniPCB Version 2.  This design uses the Teensy3.2 or Teensy4.0 and is a nice compact two axis telescope mount controller with good performance.

This PCB is designed fit (slides into) this enclosure: Aluminum Enclosure Electronic DIY PCB Instrument Project Box Case(100x71x26mm). The included case flat end panels can be prepared with very careful drilling, cutting, and filing to provide openings for the various connectors.  Better, if a 3D printer is available the panels can be printed with little time or effort from these design files.

The very affordable EasyEDA service can be used to order this version of the PCB (or obtain the Gerbers.)  You can see a comparison of micro-controller features here (again, this is an Teensy3.2 or Teensy4.0.)  The BOM with most required components is present in the EasyEDA schematic.  That gets you most everything except the Teensy, stepper drivers, and 0.1" pin and socket headers, these can be obtained Amazon, eBay, etc.

Whatever you build use an appropriate DC rated fuse (current rating depends on stepper drivers/motors/etc.)