The drawing is kinda shaky as an engineering drawing, but I'm making the best of it. A well-drawn model will have all dimensions referenced from a single point, typically for this one, it would be the lower left corner. That's not a big deal, as I can do the math and get correct results. Questions to be answered are preceded by stars **.

There are some missing dimensions and some ambiguous ones as well. The answers may be in the drawing, but they are pretty well hidden/obfuscated/located in an unusual manner.

You have a 1/4 square block in the lower left corner. The diagonal dotted line with 3/8 at the end of it is ambiguous. The diagonal of a 1/4" square is 0.3536 inches, not 0.375 inches. There's no need to have a diagonal dimension if the other two are provided. ** Please confirm that the 3/8 dimension is meaningless?

Please also confirm the same for the right side corners, top and bottom. The diagonal of a half inch square is 0.70 inches, not 0.75 as shown in the drawing. ** Another meaningless dimension?

** Does the 3/16 center notation in the lower left corner mean that the hole is to be 3/16 inches diameter? I hope it's not that large, because that leaves a too-thin wall on the standoff, a thirty-second of an inch at the very edges.

The four standoffs in the lower right corner are almost clear. The dimensions of the standoff are in a good location and the y-spacing and x-spacing for the set as well as the y-delta are in the drawing, but it seems to be missing the x-delta, the distance from the edge of the drawing (left edge or left inside, either one). As the rest of the drawing references the inside of the walls, let's be consistent and provide that figure based on that reference.

** The upper left standoffs have most of the necessary information, but in this case, it's missing the x-delta and the y-delta figures. Again, it should be referenced from the bottom and from the left, but if you provide it from the top and from the left, I'll do the math.

** Can you clarify the note to the far right of the drawing, "standoff inner = 1/4, center 3/8 from inner corner" ? To which standoff(s) does this apply? One typically does not measure on a diagonal, so I would not apply it to the dotted diagonal lines in the corners. If this is a reference to holes in the right side standoffs, it's peculiar, as one would simply center the holes in the square cross-section.

I've been running over the drawing for too long tonight and will have to get back to it tomorrow. I'm sure there will be more questions, but you've given me a good bit with which to work.