Schwinn made Tubular S-2's in Hungary till the end. There are many different rims that look like an S-2 but they are not Tubular and some do have the knurling on the face. I've had some Schwinn 26" S-2's that were produced in the late 70's or early 80's but they were not stamped with "Schwinn Tubular S-2". These were rolled out of tubing so double wall and there were no other manufacturers that made rims like this as far as I know. If it doesn't have the holes in the shoulder it's not an S-2.