Tom,

From photos of the exterior front of the panel only, we are only guessing.

Do you have any photos of the panel with the cover off?

Did it have the "L" shaped bus bars and did the breakers have those long slots which fit over the "L" bus bars?

If so, they will be the same as Zinsco, if not, then they are likely something else. Looking at the shape and color of the breakers ... like everyone else ... they sure look like Zinsco, but ... what did the inside look like?