Actually there are much more issues with old code on new servers that anyone out there not working in Software Engineering even can imagine. Different Compiler Versions produce different results, Kernel-Implementations for Memory Managers may differ, CPU differences cause issues with multithreading (2 cores on 1 die is different from 1 core on 2 dies etc.). you would basically need the old servers from back then, i doubt they still have them around. It can be done but it might involve more than just a "few" tweaks.