Heating Help

Buderus G124x leaking

Drew just called from a customers house and relayed that the return elbow on the bottom left of the block is perforated/rusted through. On the parts diagram (p/n 05407352) it appears that the elbow is secured to the block with a jam nut and gasket behind it. On the boiler in the home, it looks like it's a bushing. Things are so corroded it's hard to tell what we are looking at.
If anyone here has had one of these apart and could tell us what the configuration actually is please call Drew at 231-920-7471 . Tech service call center @ Buderus was no help in determining how this piece is actually put together. We don't want to try and take that bushing/jam nut out unless we have to. Going to try and clean up the threads and seal up with some thread cord.

Thanks
Steve