The Aero ektar 7" is a very good lens but will only cover 4x5.
The Graflex 15" Tele-Optar /5.6 is also an extremely well lens but also will only cover 4x5.
I personally own a 15" Tele-Optar and use it often. (I would equate it to a 135mm lens on a 35mm camera as far a focal length goes).

The 5x7 Speed surprises me... I have never seen a 5x7? It must be pre-1930's

You got one heck of a good deal!!!