Both solutions are made up of a PCB with 6532 + ROM and glue logic. The defective 6530(s) need to be replaced with an IC socket, the replacement board is fitted in the IC socket on top of the KIM-1.
Which one you choose depends on the state of the KIM-1. If only one of the 6530s is damaged, the Corsham solution is the right one. If both 6530s need replacement the Eduardo Casino design is the appropiate solution.