Contact Taurus Customer Service at (305) 624-1115
go to the SHO STORE site (as in Taurus sho) and the TCCA (Taurus car club of America) site
look on another site.
Try gun shops, pawn shops, garage sales, want ads, for sale ads, estate sales, egunparts.
It is hidden behind a plastic shield underneath the car, just before the rear, passenger side tire. See the following site for details: http://sites.google.com/site/redcapsmiata/tutorials/fuel-filter-replacement
If you are hitting the target low, you raise the rear site.
Ruger has sn information on their web site.
Try Davesace site or mosquitocontroltrap site. Both have some replacement parts or might be able to special order or refer you.
eBay
colt gun collectors site has the info, google it
Sears has an 8" replacement 5x magnification mirror on their web site
You can request a owner's manual for fee at the S&W web site.
Ruger has a serial number search function on the company web site.