Not sure if you care about those stuff. Either way here it goes (derived from ScanMaker 4800):
# diff /etc/udev/rules.d/60-libsane.rules{-backup,}
833a834,835
> # Microtek ScanMaker 4900
> ATTR{idVendor}=="05da", ATTR{idProduct}=="30d9", SYMLINK+="scanner-%k"
1885a1888,1889
> # Microtek ScanMaker 4900
> ATTRS{idVendor}=="05da", ATTRS{idProduct}=="30d9", SYMLINK+="scanner-%k"
