Sorry, not clear what you are asking. The previous responses to you said the new Image would work on the old hardware or is it you want to update the Pi?
When the Pi 4 was released they swapped which side the Ethernet port was on the Pi. If the end with the USB ports on it has one large hole on it for both USB and Ethernet, it can be used for the Pi 4 and older models. If it has 3 separate cut-outs, the Pi 4 won’t fit.
I hate to bring such an old thread back, but I wanted to thank everyone that helped me. I was able to swap the device out for a 8gb RPI4 and new SD card. I downloaded the latest image, and flashed. Imported the back like everyone had said, and everything worked great.