(I've been looking for some Polish bossa nova for some time
You may like Nasza Basia Kochana
One of their song "A dream found in forest", 1975 is here: wrzuta.pl/audio/4XJTGoVmub/nasza_basia_kochana_-_sen_znaleziony_w_lesie
Taduesz Nalepa (and Breakout) in blues and SBB (Jozef Skrzek) in progressive rock are both legendary in polish 70ties music.
Novi Singers like vocalist is Ewa Bem, her bossa nova record: chazzforjazz.com/servlet/the-761/Bemowe-Frazy-Ewa-Bem/Detail