So I've seen a few more pics and I'm inclined to now see it being 'as supplied'; not least 'cos the counterbores in the original picture don't look like they've ever had nuts tightened up in them, the lock mechanism is indeed by split cotter, and the casting is shaped to accomodate the counterbore for the single nut.
I'll make an album & post some pictures in due course, I've only just got in….
Also the table and overall condition look nice for a vintage machine, so I'd call it all good.
..with these machines (and here it'd be useful to have other views), I found that the bolts that hold it to the stand need only be nipped up lightly to start with – when I first put mine on the stand I bolted it down firmly and then wondered why the the table travel felt so stiff.. ..'feel your way' with the handles as you gradually tighten the base bolts down.
Then cut some metal and give the machine a few hours hours work to settle it all down, and then you can start to make adjustments and deal with any issues as they make themselves apparent.