Ok sounds like it shouldn't be too difficult to solder then.
Make sure you clean the area right up with emery paper so it looks like brand new copper before you attempt to weld it up,don't breath in the smoke that will come off it. There will be refrigerant still trapped in the oil in the system and as it heats up it will boil it off and create a toxic smell.
Good luck with the R12

Let me know how it goes.