Remade the part using 3/8" plate. Bored the center hole on the lathe. transfer punched the holes, drilled 5mm holes close to the bottom using drill stop on the press. Tapped using a M6 but I need a bottoming tap to get all the way down. Have one on order.
The one I made came out nicer than the waterjet part. I spent hours laying those out in CAD, took 30 seconds with a transfer punch and the holes are more accurate.
You can see the stock donut gasket so I used some longer button head M6 bolts I had. I also clocked the fuel pump so that it will fit in the corner of the square tubing.