It is my understanding that there were three 128K to 512K upgrades done by dealers.

The first simply replaced the 128K logic board with the 512K board and moved the ROMs from the 128K to the 512K.

The second is as above, but it included replacing the 128K ROMs with the new 512KE ROMs.

The third is like the second but included replacing the 400K floppy drive with the 800K floppy drive.