I designed a physical modelling synth [mimba] in Pd, it's mainly Karplus-Strong. Documentation, sound samples and downloads are on www.hansroels.be/mim.html
It's an early version (0.90): there are still some minor bugs and it's not really cleaned up yet... It's also rather complicated... but I've created some nice presets (guitar, organ, percussion-like sounds)! I hope you enjoy my work.