The 6061 alloy is primarily for "wrought" applications rather than sand casting. It would be problematic for sand castings.
That said, I have acquired a Jennings Sportsman of the 1935 variety. It is painted black, and the black finish is original to the machine. I found it really heavy to move and upon opening it up found seven 1.5 large dry cells corroded, leaving a white mess on the wood. All the wiring was gone associated with wiring the dry cells.
The machine is not functional and has a white like coating on all of the internal metal. Maybe from the dry cell corrosive gas and storage high moisture.
This is not a problem that can't be resolved by cleaning. But I am missing the four outside leg bracket caps. I have one original leg to the machine that is painted black and has the metal bottom leg tip. The other legs are finished natural with what looks like silver paint for the leg tip.
I need the outside leg bracket caps. I do not have an example of the outer bracket and since I am located in a dead zone for pinball as a whole in Harrison, Arkansas I have to hope I can get some help and advice from a pinsider.