It sure looks like the same construction as the current SG Bass, but it's odd that the coils are visible. Where are the tops of the bobbins?
Definitely not a mudbucker. Certainly not original equipment on a late 60s EB-0.
Another view of the current pickup, from another thread:
Hey that's my hand! lol Yes, this is the current SG bass pickup.
This is a REALLY stupid design. The pole pieces are fake.
Here's all the things wrong with it; they used mini guitar humbucker bobbins... OK not too bad I guess. They have steel blades in them that are shaped like an inverted T. In my opinion the blades are in upside-down, because this way they don't extend past the top of the pickup, and are too far from the strings, because of the aluminum fake pole piece screw holder. Ad that brings up to that thing. They used a big chunk of aluminum, probably thinking since it's not magnetic, it's OK. But adding a conductor over the coils, especially aluminum, will cause eddy currents to form and suck the life out of the tone of the pickup.
Here's some more photos:
Here's the top without the aluminum thing.
You can see the ceramic magnets on the bottom of the blades here. You can also see the T part and hot far under the coils it goes.
I got this to rebuild for a customer, and to also make a new bridge pickup.
So I rewound the coils and machined a steel keeper bar for the pole pieces and made a small sidewinder using neodymium magnets. So it's like a junior mudbucker, but without the mud. The customer wanted a bright clear tone.
The problem with the original was it wasn't a mudbucker, and wasn't all that clear sounding.
I didn't get the cover, but here's a vintage mudbucker cover I used to check fit. It fit the SG pickup, so I know the spacing is the same.
The new neo bridge pickup.