I just tossed in both basswood and silver maple in the OWB tonight; got the trees from a guy in town on a city lot, trees were very old, the size of those in the OP's pictures. Surprisingly, the trees had no center rot, and the landowner took what he could for logs to a local mill, and while I was taking the scraps from his yard, I said I was amazed a mill would take silver maple, and the guy says the mill don't call it that, they had another name for it, can't remember what it was. Anyway, like Cbird 14 says, if it's light and cuts with little effort, basswood is a great guess, if heavier, then silver maple. The pics show a little twist or angle to the bark, so I'd lean towards the silver maple.