Nothing special about the starter relay in a BJ60. Other than it has toyota printed on it and a white connector.
You could just buy a standard relay in the appropriate amperage rating. Two big wires go to the big lugs, two small wires go across the field coil of the relay. When the little wires energize the relay the big contacts connect.
You need a normally open relay(no continuity while off across the large contacts)
Me personally would run a new relay over a used Toyota one. But the used Toyota one bolts easy to the fender and has the connector, which you would have to cut off for the generic relay.