I am not sure how recently this happened, but I just found a note tucked away on the Shield Wall Games site explaining that the company has ceased operations.
At the time of its demise, Shield Wall was offering a 20mm modern infantry range with a focus on the US army. According to TMP, in 2007 Shield Wall purchased the Faust Studio line which had previously been sold to Second City. The Faust line included 20mm vehicles for World War One and Two, as well as several 25mm ranges.
The photo below shows one of their Modern subjects. It was listed as "Modern US Troopers pack 10." (The picture is from their website.)
Anyone with further information on the fate of the Faust Studio range, please add a comment below.