Trying to replace ancient bifold door top roller

Top roller for lauan hollow-core bifold closet door (maybe as old as 1960) is so worn out I can't even tell what the roller diameter once was.  It once had a spring which is now missing.  No brand or number markings on door or hardware.  The slot in the track is only 1/2" wide and the inside width of the track looks like about 5/8" wide so a standard 7/8" diameter roller won't fit.  Can you recommend a replacement roller?  If not, would a pivot pin like the #23-115 work?  Or should I just replace track and all the door hardware with modern ones?  Thanks.