If it's an import Strat with
an Asian-made bridge, those
screws have an ISO thread as
used in stereo equipment and
TVs -- the same thread is
used for the mounting screws
of a PC's CD/DVD drive. IIRC
the older, U.S.-made Strat
bridges used 4-40 machine
screws. The springs are
nothing special, one from a
click-style ballpoint pen
should work fine, although
you might have to shorten it
a bit. If you get stuck,
just e-mail me and I'll send
off a few from my extensive
collection of miscellaneous
guitar hardware. :-)