Chosen Solution

Can I buy the metal housing of a 2017 iMac 5k and use it for a 2019 5k iMac? What about LCD’s? If my 2019 screen is damaged, can I buy a 2017 screen, with the same model name?

I don’t know of anyone going to this extreme! Apple is good about its parts numbering so parts which carry forward are the same P/N. If there is any differences it gets a new number. So… looking just at it this way we can see 2019 iMac 27" Retina 5K Rear Housing Unit, Apple P/N 923-03064 Vs 2017 iMac 27" Retina 5K Rear Housing Unit, Apple P/N 923-01666 are different! Are you sure you need a new case? You still need to transfer parts over and there are some sundries that are needed. As far as the display: 2017 iMac 27" Retina 5K LCD Panel & Front Glass Assembly, Apple P/N 661-07323 Vs 2019 iMac 27" Retina 5K LCD Panel & Front Glass Assembly, Apple P/N 661-12558 again, the part numbers are different!

i found this link re the question : https://witcomputers.com/product/imac-27