The Dawn 100L was a light-pattern cast iron engineer’s bench vice with jaws that were 100mm wide (4″).
The handle is quite skinny by Dawn’s usual standards – 3/8″ in diameter or so:
The handle is 6.5″ long:
The jaws are 3D printed replacements for the missing originals, which is why they are an odd colour:
You can still somewhat make out the sticker:
The bit at the bottom appears to say “A Division of Siddons Pty Ltd” or similar – suggesting that this vice was made during the period where Dawn were owned by Siddons – so 1973 to ~1991, as far as I am aware.
The light pattern vices are definitely true to their name – the handle is skinnier and shorter than the standard pattern vice, and there’s less metal in the casting. If you’re after something for heavy duty work I’d keep looking for something stronger, but for light usage it seems perfectly adequate.