The gun pictured has hex screws installed in those drilled and tapped holes.
Rangers and Commandos are similiar in most ways. Biggest differences usually are:
-Bolt is not velocity adjustable
-Body does not have a quickstrip slot
-Body (long snub for Rangers and short for Commandos)--early Commandos sometimes had painted brass bodies too
The Commando pictured is a late "transitional" model and has the billet Sniper 1 style grip frame. Older Commandos have a different style frame that is larger and has wooden grips.
Rangers had factory bottomlined frames and "WGP Ranger" and a serial number engraved on the rail.