At first I thought that it was not likely that Ford would run such a short batch of weights. Then I noticed that the weights were adjusted by drilling and /or adding lead. This is as opposed to milling or having a more refined method of casting.
So now I think that they were probably made in a short casting run. Then they were adjusted and cleaned up.
I think it is possible, even likely that they were made by Ford. Too bad there isn't better provenance.
Chilly