Civic Opera Building
Location: Chicago, IL
Built: 1929
Height: 555ft/169m
Floors: 45

6.75" Model Dimensions (1:1000 scale)-
Height: 6.75in/17.1cm
Length: 4.75in/12.1cm
Width: 2.5in/6.4cm

9" Model Dimensions (1:750 scale)-
Height: 9in/22.9cm
Length: 6in/15.2cm
Width: 3.25in/8.3cm

13.25" Model Dimensions (1:500 scale)-
Height: 13.25in/33.7cm
Length: 9in/22.9cm
Width: 4.75in/12.1cm

Summary of Model Scales:
6.75in (0ft 6.8in)/17.1cm: (1:1000 scale)
9in (0ft 9in)/22.9cm: (1:750 scale)
13.25in (1ft 1.3in)/33.7cm: (1:500 scale)

The pictures shown are of the 6.75 inch model.

The second picture shows the 6.75in, 9in, and 13.25in models.

The larger sizes have slightly more detail.