You might want to send Jake Raby a PM, he'd know whether the intended repair would be robust. If it were me, I'd source a used one and have the local indy swap it. You might also check the local scene, if it can be repaired it doesn't necessarily need to be a Porsche enthusiast who does it, just someone who does that kind of work for a living.
PS If you are not too fussy and just want to end the leak maybe something like this would work, I read in Excellence where it was great for fuel tanks how is it on tranny oil leaks? uncertain..
http://www.dowcorning.com/content/etronics/etronicsseal/etronics_aas_1ptov.asp