Chosen Solution
Will the Item number: 2015 4K iMac screen replacement (IF173-048-1) work in the iMac Retina 4K, 21.5” 2017?
There are a few differences with the assembly, I wouldn’t swap them out. Use the correct one. Reference, Retina 4K iMac 21.5" LCD Display Panels: 2015 - Apple P/N 661-02990, Display ID - LM215UH1 (SD)(A1)2017 - Apple P/N 661-07322, Display ID - LM215UH1 (SD)(B1)