I have an ongoing project to build some Berlin '45 terrain and on looking at the Battlefront Flames of War website I noticed that they produced a Pz IV turret bunker. That solved that , I hated the thought of that nice looking turret being consigned to the spares box for eternity.
I pulled the page up on the BF site on my iPad as inspiration and then measured and cut the pieces. The top part was plastic card and the bottom part was cut from the the back of an old picture frame. I cut the bottom off the Pz IV turret to make it flush and then drilled a central hole with the pin vice. I was a little overzealous here and ended up drilling all the way through. This actually turned out to be helpful though as I placed this in the correct place on the bases and just drillled through the lot with the old pin vice.
To add some texture I glued some wet and dry paper to each rectangle and then stuck them together with PVA. When it was dry I painted with various shades of grey. I think I used Privateer Press Bane Base and then Coat D'armes dark grey. I then drydrushed lighter shades of grey. The turret was attached with a piece of brass rod. I carefully filled the drill hole with green stuff and built up the missing piece of rim with green stuff.