Picked these up today, Bulk pick-up time in my area...
first I thought it was a tire spreader, but?
~3 feet long, hinged with swivel hooks & adjustable hooks..

ladder brackets to hold a scaffold plank??

2nd the ladder jacks (think that is what they call them) got a set in one of the sheds?

Thank you for the replies!! Great! I can use them!..  Just clean them up, oil, & preservative..

checked EBay for "Ladder Jacks", they had a few, but reviews were negative compared to new aluminum models..
http://www.ebay.com/itm/steel-ladder-jacks-2-/301581414533?pt=LH_DefaultDomain_0&hash=item4637a73085

Aluminum ones are harder to find free..............