Here is a timeline to help date Vera scarves using the signature printed on the scarf.

1947 - mid 50s: The earliest scarves were signed vera in a very small print. All the letters were lower case. 

Late 50s- The Vera signature became capitalized.

Early 60s: The ladybug symbol and  © copyright symbol (registered 1959)  were added to the Vera.  The signature and the bug were about the same size.

Mid to late 60s: The ladybug was used less and less, and the signature got larger.  The ladybug became much smaller than signature.

Early 70s: The Vera signature continued to get larger and bolder.  Usually no ladybug.

Mid 70s: Bug sometimes present, but disappears totally after 1976.

Late 70s: Signature started to slightly shrink.

80s: Smaller signature with  © copyright symbol.

Vera died in 1993. At that time her name was licensed. The post-1993 scarves have a small "vera" signature and the copyright symbol.