Ancient resurrect all right. But you've done me a service. I notice that I failed to mention that my 3x13 jazz combo is maple on the outer ply but mahogany on the inner ply. There are examples of shells with all possible combinations from the later 50s through the 60s: maple inner and outer, mahogany inner and outer, mahogany outer and maple inner, and maple outer mahogany inner. They all share the poplar inner ply and maple re-rings.
Meanwhile, if you substitute Compacto for Impacto, you are correct. Rob Cook's The Ludwig Book (p261) gives production dates for these 4x14 snares as 1956, and the Downbeat from 1960-1970. But I wouldn't be surprised to find well documented Compactos from 1957, 1958, etc. New ones are coming to light all the time, and Rob Cook's book is from 2003. I don't know if it has been updated.
The only question I'd have is about your strainer. In the picture in the Cook book, it is shown with the "beer tap" strainer, which is different from the downbeat strainer. You can see the Downbeat style strainer in the picture of mine above. Is yours like that one? Or a "beer tap"? (I'll have to rustle up a "beer tap" picture if you don't know what one looks like and can't be sure which one yours is).
And as Mike says Welcome He got his post in while I was filling out and cross checking the details in mine.