My clip (plastic type) snapped in two where the screws go when it was fairly new...possibly a common prob? Rang SH /Yaesu UK distr and they kindly sent out a new one FOC.
Most chandlers should have a SS clip for very ittle money (assuming you're talking about a button-on-the-back-of-the-mic type mount.) Just installed one on my boat after my epoxy-glob repair gave way (it held for about 6 months; longer than I anticipated it would.)
The SS job can be adjusted for tension by bending the center prong. I think I paid about $5 US at an overpriced boating store.
I would guess that a radio shop (like shortwave and all that stuff) would carry them as well. The button clip is a standard setup in radios (Motorola used to use it on their old cell phones, as well.)