What do you mean by "hard to work with"? Are you saying that the wood is hard and dense (not easy to cut)? Looking at the wood I'm not seeing a lot of pores so I'm inclined to think it's a variety of maple (especially if it is heavy). The legs are built so you can use the upper piece for joinery. It's a bit small for mortise and tenon so I'd think the former home owner was using dowels or possibly pocket screws. Any of these methods would be strong enough for tables like you've shown. Go buy some maple if you want the wood to match. Bring along a leg to match color with the boards you're selecting.

Yes, the wood is dense. And you're right about it being maple, I'm pretty sure it is. But when I say its difficult to work with I mean that I basically don't know what I'm doing and I need a jig or something to hold it in place while I screw other wood to it. I know very little about joinery so I'm kind of in the dark. Here is a pic of how I used two screws to attach the pine frame:

Those legs are for coffee tables. There is a metal corner brace designed to attach the apron, just as you have done.

If you have these brackets, you will find the legs much easier to work with!

Here is a link that might be useful: what you need

Metal corner brace as described in link below. CLick on more info then technical document for all the information you need on how to install.

You could also use mortise and tenon (more difficult) or pocket screws (quick and easy), but the metal corner braces are a good compromise between ease and strength. Many commercial dining tables use them.

Here is a link that might be useful: metal corner braces

Absent access to a hollow chisel mortiser setup, the metal braces are probably the best choice.

very helpful, thank you all very much.

Anyone want to take a stab at what kind of wood it is?

As above-mentioned, maple.
Casey