Yup. Those are weep hole covers covering, uh, weep holes. The weep holes are slots that drain rain in the outside window tracks and condensation from the inside tracks outside so that the water doesn't cause problems inside.
Good luck finding replacements. I finally covered our weep holes with black electrical tape with a bump in the middle to allow drainage.
Don't just tape them off, water's gotta drain, somehow...
2014 Sunstar 31KE
1988 Suncruiser 31 RQ
1968 Travco 210