tach woes

[Tim]

Hi All,
I have a '99 900 SS with the annoying bouncing tach needle problem.
I know, tighten the three brass screws.
Well, I've done that a million times (lasts two maybe three days). So on the one million and one time, I added removeable locktite. Of course, that is the time I gave her a little to much "thunder and lightening" and I broke the internal bolt for the brass screw (amazing what you can do with a blade screwdriver). Now I am literally "screwed".
Is it possible to take the tach apart and replace the bolt?
Does anybody have a tach they want to sell PLEASE.
Thank you in advance Folks!
Tim