Help dating a Schick Krona

[Dolle]

I have a black tip TTO Schick Krona. The backplate is stamped 2 3 0 M.

The doors say "Schick" and "Krona"

Anyone?

 

[Twelvefret]

Schick Krona

 

[Dolle]

Thanks! So 1967-1968.