Technical bullet style wheel dust caps?

I just got some chrome bullet style dust caps from united pacific for my 52 Lincoln.
There is a threaded bolt and nut that comes with it obviously to bolt on to the center of the wheel , but I have a cotter pin in the center. Did i just get the wrong style cap for my ride or is there something else im not doing. ?
thanks for the help.
ill try to upload a pic

 

Yup, You probably wanted the push thru style.
That one that you have is for elsewhere on the car.
KK

 

I think you just have a chrome bullet. Maybe you can drill a hole in the center of your stock grease cap, screw the cone onto the cap and snap it on that way.

Bad idea to bolt on any kind of wheel accessory using the spindle nut.

 

Thats a good idea Squablow..... i didnt think of doing it that way.
Thanks.