Doug: The JET mini definitely has a MT#2. What you have done is remove the entire live center "AND" the spindle from the tailstock. It is the spindle that has the thread that you see. Put the spindle back in the tailstock and turn the handle clockwise drawing the spindle back into the tailstock. When the spindle is fully back in the tailstock you will feel the handle stop turning. Twist it about another 1/4 turn.....it will require some significant force...,..and the live center and its shaft(the taper) will pop out of the front end of the spindle.
You can buy a 60° live center from www.littlemachineshop.com for about $21 including shipping. "DO NOT" get the heavy duty one!!! It will give you trouble as it is designed to be used in big engine lathes. The standard duty center(stock #1189) will be just fine.