Did a major refresh on the RS last couple months and had these repaired by my local shop when I didn't think I could find any new OEM units. After my interplanetary search I found two in Slovenia of all places. Anyway He used a combination of techniques but basically smoke tested them, Marked the leaks and then put a negative pressure on the intercoolers and vacuumed in the epoxy. Pressure tested at 20 PSI. Smoke tested again and no leaks. The leaks we not to terribly bad to begin with.
Now of course I don't know if they would last 2000 miles or twenty thousand miles but he got pretty serious about the repair and I feel like he did a pretty sweet job.
Anyway I paid him 450.00 for the repair so would sell for the same just to recoup the expense
PM if interested
Thanks