Drove past this many years ago but no longer have the photos. However, you may find some nice shots of the ruins here: https://commons.wikimedia.org/wiki/Category:Pass_Strub,_fortification?uselang=de

I not yet consulted, recommend Maretich von Riv–Alpon's account of the fighting there in 1805 and 1809 (unfortunately, no diagram of the position).