Kevin,
The 5gal is correct to Fill from the Top as plumbed.
I see you are missing the selector handle [1-5 gal] & the external pump w/ handle, quick shut off gate valve &/or Totalizer [not all came w/ totalizer].

Reproduction/Fantasy Cans
http://i124.photobucket.com/albums/p2/oldegaspump/AllCansMASTERTHUMBNAIL_zps4bfdbbc7.jpg
Rnd Can Re-lids