You have a few options if you want to stick with a Panasonic/Schwinn. All of the '85 -'89 Schwinn Peloton, Circuit, SuperSport, Tempo, and some of the Preludes were Panasonic-made and had 74* st/ 73* ht angles, with the Pelotons and Circuits made from SL/SP and the rest with Tenax tubing. All should give a very similar ride to your current frame.