No. There are two reasons for this:
1. An SZ1RV1202 potentiometer requires a 10.5 mm drill hole for installation, whereas the enclosure has a 22.2 mm drill hole
2. The intermediate metal contact fixing plate does not leave enough space below the front panel for the potentiometer body
Solution: Use the XACB or XACM boxes with XB5 range potentiometers and potentiometer heads. See attached catalogue page for potentiometer options (taken from Harmony XB5 Catalogue November 2019).