Roger Penske used one to tune his Cosworth DFV Indy car engines, his name was right-on the box!
It appears the leads are color-coded, are they? Then all you need to do is make the connections that any 1970's Motor manual would tell you to make to get readings. Check your local library, they usually have copies of them for loan.
I have what I believe is an earlier version of that box, it's in storage, so not handy right-away. I've had it since it was current, and I owned vehicles with points and condensers. Kevin Cameron of Cycle World said awhile ago he just recycled a bunch of old meters, and now doesn't own a dwell meter. If you like things explained in mechanical issues, he's a great read. He usually gives a good historical perspective on whatever's on the table, or under discussion.