Even though the 5510 was revolutionary, it technically wasn't the first phone with an MP3 player. The Siemens SL45 introduced this feature almost 4 months before, in August 2001! : r/vintagemobilephones
Charger With Plugs Siemens 20,30,40,50 Series; Siemens 50,60,70 Series; Siemens St65, St60; Benq-siemens - Mobile Phone Chargers - AliExpress
Mobile phone mains charger for Siemens C35/A35/A36/A50/C25/C28/C35i/C45/C45i/M35/M35i/M50/ME45/ME45i/MT50/S25/S35/S35i/S45/S45i/SL42/SL45/SL45i/SX45 Charging Cable/Power Supply/Travel: Amazon.de: Electronics & Photo