I'd always wanted to do a Sturmi conversion - the crazy Finnish "upgrade" to the StuG assault gun by adding logs to the side armor and concrete over the glacis plate - but I'd traded the majority of my Finns away for more German and Hungarian items. Imagine my surprise when I found several great examples of concrete "armor" added to late StuG ausf. Gs by some Germans in a few books and online!
While it was not a widespread field modification (and its combat value was probably negligible, at best), I thought it would be an excellent way for my StuGs to stand out from most.
The base miniatures are all PSC StuG ausf. G (Late), assembled as normal. I then added the concrete "humps" to the casemates, textured them with an old toothbrush, and added the rebar once the GS dried.