O'day traveler track
Unless O'day changed suppliers along the line, the track for your manual system was made by Schaefer. The size, however, is discontinued and noone makes cars to fit it. One rigger gave me a quote for a sort of jerry-rigged system in which cars would be adapted to the track, but I wasn't comfortable with it. I bit the bullet and put in an entirely new Harken system. Since it is a mid-boom arrangement, the loads were on the margin between the mid-size and big-boat system (at least then--1995). I sprung for the big-boat system and have been very happy with it. I agree with the other response that the manual system is unsafe. The traveler is not adjustable at all in any kind of wind, and the trimmer is in an awkward and dangerous position over the companionway. My advice is scrap the system and start over.