One tricky aspect of the Tempest has always been the cocking of the action. The first step is to unlock the barrel latch, which is on the left-rear of the main body. Push the lever forward and the top of the steel latch comes back, allowing the barrel to be pulled upward and away from the breech seal. You have to grip and swing the rifled steel barrel through 160 degrees away from the pistol body, until the trigger sear engages and holds the piston back. There’s a larger diameter knurled section at the rear of the barrel to creathe a secure grip for the user. There is a knack to cocking a Tempest, so if you are struggling, try resting the gun on the front of your thigh and pulling the barrel down over the front of your leg. Then immediately apply the safety catch, which is on the left side of the grip behind the trigger - push up to put onto ‘safe’.
Always apply the safety catch before loading the gun. I would recommend you do this because you have to let go of the barrel once cocked, to load the gun, which leaves the barrel unrestrained when you are selecting a pellet. Taking the barrel back to rest on the top of the barrel locking saddle is a good idea, but applying the safety catch avoids any accidental discharges
Only a collector could tell this from an original.
The left-hand grip with the large curved thumb rest.
My two-handed hold worked well.