The overall design is based on the BSA Model 1949 prototype shown below as compared to the Sterling L2.
|BSA Model 1949||Sterling L2|
Sterling MK7A4 Paratroopers Pistol- Current Version
The DH-17 seems to be made from highly modified Sterling L2A3's. Remarkably the base gun of the blaster prop greatly resembles the Sterling Parapistol pictured above, however, it was discovered that that gun was not produced until 1983.
Details were then added to the front of the gun to make it somewhat similar to the BSA Models. Details of these added pieces are not known at this time. A rod was added between the rear and front sights. To this rod was attached, with standard scope mounting rings, a casting from an old Single Point red dot scope similar to the one seen below. A small detail piece was also added just to the right of the rod above the grip
Single Point Scope
Made in England by Singlepoint (Great Britain) Ltd.
Photo: Richard Jacobsen
Another major modification to some variations is in that the magazine holder/port on the left side of the gun was removed so that the props would fit in the holsters on the right hips of those who carried them. This can be seen at the beginning of A New Hope in the versions the Rebel Fleet Troopers carry. It is believed that all the versions like this were castings of the "master" prop, the main clue to this being the rather thick trigger guards on the props, and that the holder/ports were sanded or cut off of the castings.
It is also of note that while the majority of the prop guns were castings the scopes are not. (see below)