Yes your model is the New Square wire ( aka Sq wire 3.0) from the mid 2000s. The Sq Wire II ( not to be confused with the Sq Wire 2.0) came out last year.
The Big Square Wire is a larger version of the Squre wire 2.0 for those that found the Sq Wire 2.0 too small. If you lived in Australia you had the Square wire 2.0 30mm to comply with local laws - it was still smaller than the Big Sq Wire.
None had interchangeable lenses ( other than Sq Wire 2.0 spring and non sprung).
The Big Square Wire is a larger version of the Squre wire 2.0 for those that found the Sq Wire 2.0 too small. If you lived in Australia you had the Square wire 2.0 30mm to comply with local laws - it was still smaller than the Big Sq Wire.
None had interchangeable lenses ( other than Sq Wire 2.0 spring and non sprung).