Complex sentence: The project was discontinued during development and only two chassis were built, and those chassis were later rebuilt and served as testing platforms for the "Artillerikanonvagn 151" and "Stridsvagn 103" projects.
Split into simpler sentences: The project was discontinued during development and only two chassis were built. They were later rebuilt and served as testing platforms for the "Artillerikanonvagn 151" and "Stridsvagn 103" projects.