Highground

This gives us an idea as to where the term 'sidejob hack' comes from and what it used to be like doing electrical work before the box stores.

Seems to be a lot of work and time to cut the sides out and brase those two boxes together.
A lot cheaper to get a new double box from the wholesaler unless it was way out in the whops and a long distance away from any electrical wholesaler.

It looks to me that this is a pair of those ultra-shallow, non-approved boxes. They probably aren't made in 2-gang.

Don't even the shallow "handy-boxes" have KO's on the back? I've never seen anything like this even in single gang form...

If you look closely, you can see four pry-outs on the bottom surface, and probably another four on top.