Bifold door guide.

I have 5 "vintage" bifold door guides that are in various stages of advanced decomposition due to age. I believe they are circa 1964 parts. The picture is of the best (two have been replace with hex head screws which seem to function well but I would prefer the proper parts. The rail itself is a "C' shaped affair complicating the wheel insertion (I think it would, since I have no wheels left, I'm only guessing).
I have one hole that has been enlarged and the threaded part does not ft well at all. I was going to drill a clean hole and place a dowel in it but thought you might have a better solution.

These doors are from 1964 and I think the hardware is original, so sad to see that things just don't last anymore!

Thank you very much. This may very well work. The vertical space I have is restricted and it's going to be close but it is certainly worth a shot!

I had not seen a guide w/o the roller wheel at the top and was trying to make one out with what I had, obviously they come without them. So simple yet once you get an idea in your head it's hard to see anything else.