Ok, here's the update. We carefully supported the mast at a variety of points equidistant from the bend, and applied ever more weight/force to a wrap of webbing at the bend. We arrived at a point where we were inducing 4" of bend in the opposite direction from the original bend, but upon releasing it, we still had 2" of bend in the original direction. Crank it up again, a little past the 4 inches, and it gave, kinking.
So plan B. Bought a used mast of the same vintage from Tom at Aquarius, and arranged (expensive) shipping from MN to MT. Tuned and stepped it Friday morning, only to discover the portside upper outer diamond disturbingly slack on port tack. Dropped it, once again carefully adjusted all diamonds according to Aquarius specs(several loos readings were significantly off), and took her out again. This time a portside lower inner was slack on port tack. A spin hlyd blk failure drove us back to the beach to drop the mast again. Did the drill again, and finally got the ride we've been waiting 5 weeks for. Will probably drop it one more time to check the readings, but the boat is back!
Anyone else have this experience of setting the mast up, but when taking it out and loading up the mast, having the diamonds take a less than perfect set? Or is this a particularly finicky mast?
This newer extrusion is in much better shape than our original mast, no corrosion, no dings and dents, no extra holes for different spreader arrangements. We're very happy now, feeling much better about our chancess of keeping this stick in column. And still a couple of months of soft water sailing yet here in the Pacific NW. Thanks to all who offered advice and consolation!

Dave