Another excellent, but quite dense, resource I've found helpful for implementing my own waveguide models is Physical Audio Signal Processing, a book available as a hard copy and online [1]. There are also an absolute ton of research papers on these topics which have failed to be summarized anywhere or cited outside the small circle of researchers, so there's a ton of institutional knowledge about physical modeling locked up in academic papers that isn't super accessible.
1: https://ccrma.stanford.edu/~jos/pasp/