"Why do this? How do you know that the superglue, loctite, or anything else tried, didn't mess with the other materials in that area? I realize the 501 isn't all that great, but this probably detracts even more from its value. No?"
What I should have conveyed is that I have previously conferred with Peter Ledermann about repairing the Shelter. This was back when the problem was first discovered, a little over a year ago. At that time, his take on the Shelters is that these are not all that much fun to disassemble, if one needs to remove the aluminum body, that is. I've heard from others that have had SS re-tips on this cartridge that the ruby cantilever does alter some of the character of the Shelter sound.
My take:
There is not much to lose. It has plenty of hours on it and I'm not going to attempt to sell this thing. I'll just play it til it finally dies. Currently, it seems to be playing and sounding just like its old self.
With regard to the qualities of the 501-II. I'd probably disagree with your assessment of the cartridges' inherent sonic character. I like what it does and the way it does it. That is why I've gone to this much trouble to put it back into my working line up.
That said, it is certainly no A-90 (which I've recently heard in another system). But then it doesn't try to be. It has certain sonic attributes which I value and want to hear.
-Steve