New model, two-year-old processor: The 2015 15-inch Retina MacBook Pro reviewed | Ars Technica
Refurbished: (Mid 2015) Macbook Pro 15-Inch Retina Laptop (i7 2.2GHz, 16GB Ram, 2TB SSD) Intel Iris Pro 5200, Mojave, HDMI, USB 3.0 - Newegg.com
Differences Between Mid-2015/Late 2016 MacBook Pro 15-Inch: EveryMac.com
External DVD CD Burner Player SuperDrive for Apple MacBook Pro 13 15 Inch Laptop 2015 2014 Mid 2013 Retina 2012 A1502 A1398 A1278, USB 3.0 Pop-Up Portable USB 3.0 Optical Drive, DVD+-R DL CD Writer - Newegg.com
Apple MacBook Pro (15-inch, 2015) review: Old-school MacBook Pro is good for the dongle averse - CNET
Amazon.com: Odyson - Right-Side I/O Board (HDMI, SDXC, USB 3.0) Replacement for MacBook Pro 15" Retina A1398 (Mid 2012, Early 2013) : Electronics
Apple MacBook Pro Retina 15 (Mid 2015) Review - NotebookCheck.net Reviews
820-00138-A 661-02524 Logic Board for Apple MacBook Pro Retina 15 inch A1398 Mid 2015 (IG) Core i7 2.2Ghz 16GB RAM MJLQ2LL/A MJLT2LL/A, EMC 2909 EMC 2910 - WIT Computers