I tried making a civilian Zaku (construction Zaku) using the Military and Police Zaku.
Following on from the green civilian Zaku from a while back, I've also recreated a civilian Zaku for construction use using the Military and Police Zaku. By the way, I looked around and found that this model's name is also "Civilian Zaku", and it doesn't seem to have a sub-name like "Construction Zaku" or "General Work Zaku" (like the MSV).
The right arm, which is its most distinctive feature, has shoulder and upper patrol lights from the Military and Police Zaku, elbow and wrist joints from the Military and Police Zaku's leg joints, and the rest is scratch-made plastic sheeting. The power pipe is made from elastic string used for dressmaking.
The left shoulder armour is based on the right armour of the Military and Police Zaku, and is made from plastic sheeting and a surface mount.

Civilian (construction) Zaku (GQ) style | GPO144's Gunpla works