Yea that kinda looks like what I remember, I just don't recall the big lip around that center piece, I thought that black piece was more flush(no lip) but I could be wrong about that, but I do remember using a very small straight-edge screwdriver, (you know one of those little screwdriver's that has a clip on it and ya carry it in your front pocket), to get that piece out, I remember that center piece being a little flexable, just pops in.......
Been a log time since I saw the hubcaps on my '78 but that does look real close, sadly it looks like someone has already had the tire iron on it(right side), hang on to those caps, they may be hard to find, hopefully you have the piece's that go with the cap, all 4 screws and all 4 piece's that go under the lug nuts, I don't know how hard those pieces are to find, from what I saw back in the early 80's most '77-79 Birds had that old cheap hubcap, only 2 or 3 out of 10 had the spoke hubcap like yours........
I just can't remember if that locking screw/bolt used a special key/tool that came with the car or not, I kinda recall leaving mine in the glove box, either way you'll know what ya got when ya get that cap off..............