In 1976 I took my A7 to the south of France via London. Fortunately, and for no apparent reason, I looked down at my right foot as I left the M1 having ridden 120 miles south and had the same horrible shock, oil was pouring out over my foot. The pipe had sheared off at the banjo behind the tank.
I had some small bore plastic tube in my emergency kit and inserted both broken ends tightly wrapping the pipe with wire to hold it in place.
It not only held for a 1500 mile 2 week French run with my wife on pillion but kept going for some weeks on our return.
Rather irrelevantly to this topic here's a photo of me departing Coal Aston for London, snazzy gear eh and not too much saddle room for the good lady !