I'm refinishing pine floors. I don't know what type of pine. I doubt the flooring guys knows either. The general contractor subcontracted the floors out. The sub seems like a nice guy but I'm a little unsure of his experience. He didn't say anything about filling the gaps with putty so I was just going to suggest it to him. I found a few different types of putty at the home store and wasn't sure which one I should suggest. Here's a few pics of the floor. It's a 1910 North Nj house.