The best I can tell you on this is to check the evaporator mfg plate for a make and model. Like all walk in coolers and freezer, Norlake does not break down the refrigerant side as they used what was available at the time. They puchase condensers and evaporators to assemble to there box depending on the load and location it is built for. One for Maine will not have the same capacity as one built for Arizona.
Alternate to that, I’ve repaired a lot of them with a pan spray and wire screen. Caution, the spray works real good, but is flammable at application time. It is white in color and available at most refrigeration houses. You have probably seen a product similar on TV called flex seal. Small holes will just cover over. If bigger, that is where the screen cloth comes in. If it’s the drain fitting giving you problems, You can buy a replacement form a refrigeration house.