Complex sentence: During the 1930s it could be ordered from the Norton factory with all manner of racing parts fitted-indeed such factory bikes won many Isle of Man TT races during the 1930s-many of them 1-2-3 results.
Split into simpler sentences: During the 1930s it could be ordered from the Norton factory with all manner of racing parts fitted. Such factory bikes won many Isle of Man TT races during the 1930s, many of them 1-2-3 results.