Ignition Key For 1959 T21 Bathtub

Hi, I've recently bought a 1959 t21 350 twin bathtub but the owner had lost the key. I know that the key is a two pronged affair but I'm having difficulty finding one. Can any one help or know of any websites that may be able to help.
Many thanks
Deb

 

Hi thanks for your reply, yeah I can start it with a screwdriver but wanted to keep it original and not look like I'm trying to steal the bike . I did think of trying to get one made