Here’s how to fake a Porta cipher with a Beaufort cipher:
Take your plaintext P.
Encrypt P with a monoalphabetic substitution cipher with key AOCQESGUIWKYMZLXJVHTFRDPBN.
Encrypt the result with a Beaufort, after changing the key according to the table below.
Encrypt the result with a monoalphabetic substitution cipher with key AYCWEUGSIQKOMZBXDVFTHRJPLN.
The result is your ciphertext C, which can be decrypted as a Porta.
Porta, American Porta, British Beaufort A,B A,B Z C,D Y,Z L E,F W,X X G,H U,V J I,J S,T V K,L Q,R H M,N O,P T O,P M,N F Q,R K,L R S,T I,J D U,V G,H P W,X E,F B Y,Z C,D N