How old is this Gillette?

[Purvis]

Just picked this up for $5 at an antique store.
Any one have any idea on vintage.
There are not any serial numbers on it only the Gillette logo.
The round bottom on the handle makes me think the 1930's but I don't know.
Apologies for the camera phone resolution.

 

[mr-razor]

It´s a Old Type from the 20s.

 

[Purvis]

Thank you.