Complex sentence: It was manufactured by Selmer in France and the United Kingdom, by Gibson in the USA, and by Jorgensen in Germany, and rapidly became the world's leading monodic instrument and more than 30,000 were sold in the UK alone.
Split into simpler sentences: It was manufactured by Selmer in France and the United Kingdom, by Gibson in the USA, and by Jorgensen in Germany. It rapidly became the world's leading monodic instrument with more than 30,000 sold in the UK alone.