(1) From your picture it appears that the "tube" I should be measuring for the proper diameter is solid aluminum. My original balancer had a plastic tube covering the spring which has subsequently crumbled away (see photos). The spring itself has a diameter of 55/128" so I'm assuming I should be looking at series 600 (5/8") replacement. Is this correct?
(2) Also because there is no remaining intact tube, and because the spring is broken, I'm not sure what is the proper replacement length. The twisted core measures 21-5/8" from end-to-end so, again comparing with your photo, I'm estimating a replacement length of 21". Is this correct?
