Those guides are brazed into the column. I'm not aware of any replacements. You could fabricate your own or harvest the brazed assembly from another column, or simply replace the whole column. There are a couple of lengths of column depending upon the year. Steve Becker at Bert's Model A Store likely has a used column he could set you up with.
no one makes that part that I know of. I usually cut them off another junk column. I will look and see if I have any.