I was thinking more along the lines of brazing the area where the leak is without cutting the line - provided the hole/crack is small enough as suggested by the amount of the leak. Just clean the leak area up and braze it (a professional welder may be the best person to do this). If the hole is too large, then cutting and flaring one end to fit over the other end and then brazing would work. Also, silver soldering could also work instead of brazing.
I thought about using an old inner tube to make grommets out of (I've used them for other components attached to the car - like the AC servo, very $$$ part). I went with the M-B grommets because they have shoulders on them to help hold them in the bracket and you do not want to tighten the bracket around the trans line such that it is tight enough to keep an inner tube from slipping out as I would think that may be too tight and cause another hole in the line if the inner tube slips out or rots away with age.
My $0.02 worth.
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1977 300D: 300,000+ miles
American Honda: Factory Trained Technician & Honor Grad.
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