| Westclox | Baby Ben Style 5 | Back Type | Various U.S. and international patent numbers were stamped on the backs. |
| Westclox | Ben Style 6 | Back Type | Early backs say PAT. PDG., later ones don’t. It is unknown if a patent was actually applied for or why a patent wasn’t pursued. Perhaps the design of Style 6 was too similar to Style 5 and was not considered worth the expenditure to go after a patent. |
| Westclox | Big Ben Style 1 | Back Type | Big Ben Style 1 clocks used different patent dates and arrangements on the back. Also, the $2.50 price seal, and various Westclox logos were used. |
| Westclox | Big Ben Style 1a | Back Type | Style 1a Big Ben clocks have a series of patent sequences on the back. The patents were in two different locations. Later backs have patent numbers instead of dates. |
| Westclox | Big Ben Style 2 | Back Type | The Big Ben Style 2 had two types of backs. The first has patent dates, and the second has patent numbers. |
| Westclox | Big Ben Style 3 | Back Type | Big Ben Style 3 backs had three different groups of patent numbers. The first backs have a slide alarm on/off switch, later ones have a pull switch. |
| Westclox | Big Ben Style 4a Loud | Back Type | The first backs don't say MADE IN U.S.A., later ones do. |
| Westclox | Big Ben Style 4 Chime | Back Type | All Ben Ben Style 4 Chime Alarm backs that I've seen have five patent numbers. |
| Westclox | Big Ben Style 5a Loud | Back Type | The first backs have PAT. PDG., most backs have DES.114262 |
| Westclox | Big Ben Style 5 Chime | Back Type | All Ben Ben Style 5 Chime Alarm backs that I've seen have five patent numbers. There MAY be an early back without the design patent number. |
| Westclox | Big Ben Style 5 Loud | Back Type | These backs have a USA, Canadian, Australian and British patent. The two types are so similar that I didn't record the type for many clocks I had. For completeness I am showing both types here. |
| Westclox | Big Ben Style 6 Chime | Back Type | The first ones say PAT. PDG. and later ones don't. |
| Westclox | Big Ben Style 6 Loud | Back Type | The first ones say PAT. PDG. and later ones don't. |
| Westclox | Waralarm - Fiber Case | Back Type | Early examples have a price label, later ones have the price imprinted in the back. |
| Westclox | Baby Ben Style 8 | Back Patent | The first backs did not have a patent number, after about a year a patent number was added. |
| Westclox | Big Ben Style 8 | Back Patent | The first backs did not have a patent number, after about a year a patent number was added. |
| Westclox | Baby Ben Style 4 | Back Material | Most Ivory Style 4 Baby Bens have a steel back which is copper plated then brass plated. A few late ones have a back which is nickel plated then lacquered pale gold. |
| Westclox | Baby Ben Style 5 | Back Material | Most Baby Ben style 5 clocks have a steel back. A few have brass or aluminum back. |
| Westclox | Big Ben Style 4a Loud | Back Material | Most Big Ben Style 4a have a steel back. A few aluminum backs have been seen. |
| Westclox | Four Inch Movement | Back Logo | Some from before 1910 into the teens have a maker's logo or MADE IN USA on the back. |
| Westclox | Model 66 Movement | Alarm Set Knob Fastening | Early 66 movements have screw on knobs, later they are staked. |
| Westclox | Big Ben Style 4 Chime | Alarm Governor | The first examples have a fiber gear driving a fan fly. Later examples have a brass gear driving a centrifugal governor. |
| Westclox | Ben Bolt | Alarm Dial | The first ones have a metal dial with painted numerals and a blue steel pointer. Later ones have a transparent plastic dial with imprinted numerals, and the pointer is beneath it on a painted metal disc. |
| Westclox | Windup Clock | Alarm Click | Westclox kept changing their winding ratchet mechanism. The first four types listed here engage with projections pressed out of the body of the mainwheel. |
