Hi friends,
My name is Gabriel, I from Argentina, I am sorry for my bad English.
I like to know to solve the following question,
I have two graflex 3cell flushgun, one has patent #2310165 stamped onto the bottom, the other one has the same text but does not stamped the number of patent. I have the certainty that both flash are of the decade of 40, since they belonged to my grandfather and two flushgun have the step of the age in them, the two are equal. Because this difference in the writing? are they original both of graflex?
Regards.
Gabriel.

Yes they are both original Gralfex flash units, the one without the patent number on it was made by the Folmer Graflex Corporation. In 1945 they changed their name to Graflex Inc. which is what the one with the patent number says.

They probably changed the writing to reflect the new name of the company and added the patent number for legal reasons

And your English is much better than my Spanish.

wow is true, I had not seen the detail, they are two different companies.
Now I understand, really I am grateful by his response Les.
Really Thanks.
Gaby