Taking a step back, what are you trying to switch with the relay? Define the coil voltage and load voltage & current. I guess it's a DC coil since it is a transistor relay you are talking about. The more information you put in, the more you will get out...
1970s - either a relay with an internal transistor to help drive the coil, or a transistor switch dressed-up to make it 'look like' a relay (cute box, some resistors).