Method 5:Sonication End-on

Group A: BC008

Before

After

Detail

Before                                                                       After

Before                                                                        After

Comments

Shinier, lost red residue around outer and inner ring and dirt removed (see detail).

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Group B:BC019

Before

After

Detail

Before                                                                       After

Before                                                                       After

Before                                                                       After

Comments

Red residue completely gone on the ' L' , dirt removed, purple residue removed and scrates increased in size (see detail).

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Group C: BC015

Before

After

Detail

Before                                                                       After

Comments

Red residue completely removed, dirt removed, and scratches worsened slightly (see detail).