I did a bit of searching for this the other weekend.
Im pretty sure that the sender is 3-110 ohms, from what my limited searhing told me.
Im pretty sure most toyota ones are the same, Ive modified one from a jzx90 cluster to fit into an old gauge cup, it seems to work so far (havent tested with a full or empty tank as yet)
You could get a universal one and fit a new sender to suit the gauge?