I am not an expert but I have a couple of works autocockers. The earliest works had Macdev LPRs. There are several of those new on ebay for $29.00 in chrome and black,
They then went to CCM LPRs . I do not know if they have changed their LPR but they have CCM LPRs on their ebay store now for 69.00. If you look around here and Custom cockers you can find one used.
I bought a new LPR and ram from CCM rather than buy used because they stand behind what they sell 100% ,will answer all my stupid questions when I call Mel all confused, and give great customer service.
Post up a picture when you get it together. I think their hinge frame is as good as any and their slider is better than most. Good luck