Complex sentence: As the owner of "The Guitar" it is worth noting that the guitar has never been withdrawn from sale, whilst Bruce's opinion is appreciated, he has never seen the guitar, it is without doubt the guitar in question.
Split into simpler sentences: As the owner of "The Guitar" it is worth noting that the guitar has never been withdrawn from sale. Whilst Bruce's opinion is appreciated, he has never seen the guitar, it is without doubt the guitar in question.