Manufacturing Process - Help Needed

Hi Everyone,
I’m trying to make some pieces that are larger than the spoilboard, and could really use some advice on how to get it to align precisely, as well as how to manufacture multiple copies.

I’m making a rack type thing out of wood, composed of two parts, a top and a bottom, as seen here:

For the curious, the reverse sides of these pieces contain pockets.

These parts are meant to each be 246mm in length, by 89mm wide, so they hang off one end of the Nomad’s approx 203mm spoilboard, like a tall man in a short bed:

I don’t have access to precision table saws or the like, and I might need to make a lot of these (with any luck!), so I can’t reliably cut blanks with perfect 246x89 dimensions and then just process them for the channels and holes etc. I think it’s probably going to be easiest if I do two at once on the Nomad.

Since, as you can see, the parts are symmetrical, I created a little alignment piece to fit between the top and bottom parts, and the whole thing would look like this:

Those three holes would also be drilled in the spoilboard, and dowels would go in them.

My thinking was that I would create toolpaths to process half of the thing, spin it, and then process the other half, using the three dowel pins in the center alignment piece to keep it square. I would obviously need to rotate the STL in MeshCAM to create an upside down version to do the second half.

Then I’d flip it over, do the whole process again for the reverse side, and set the last toolpath to cut off the three pin alignment piece. The pins would be removed before this happened, obviously.

Here’s my questions:

  1. does this seem like it would work? Is there a better, more efficient way? I bet there is… any thoughts?
  2. How do I zero it so it always cuts properly, no matter the exact length or width of the piece? I don’t want to have to remeasure and regenerate the toolpath for every single blank, but I also can’t be certain to cut blanks that are perfectly identical down to the millimeter. I’m working with a straight edge and a circular saw, and getting any more tools isn’t an option, no matter how much I wish otherwise.
  3. What’s the best way to fixture this? I was sort of thinking of putting some threaded inserts into the spoilboard on the right side of the dividing line where each part’s processing will halt (assuming I’m processing it in halves), and then using some kind of clamping action. Any other ideas? I can use tape, but I’d rather not if possible, for speed.

Thanks as always for any help!