You're right, I don't think it is an Aristo head.

I think the previous owner simply put in an Aristo light source that fits into the existing head. The power unit simply says "Aristo BES 23C".

So to reiterate, I don't know what a brand new Beseler 23cII comes with, but it seems that this enlarger has all of the parts/light source to make proper prints. I'm generally not concerned with the technical specificities of all of my equipment; in this case, the enlarger worked, and I used it (along with my second enlarger) for a few years and made some really nice prints with it.

If you (Bob) have any more information about the light source, I'd love to know! Thanks!