This poses a conflict:

1. If the 21 is right, then the long diagonal will end up being steeper than shown in the image with a more complete 180 turn than shown on the image. The image shows a 135° turn followed by a 45° turn at the end. For the 21 to be right, it'd use something more around a 155° turn (I'd have to calculate it - this is only an estimate) instead with a 25° turn at the end.

2. If the image depiction is to scale, there would be a 135° turn on the right edge with a 45° turn on the bottom left. The only way this is possible is if the 21 is supposed to be a 32 instead. This is simpler to make, but not much simpler.

One last question. Do you want to use 1.8, or are you okay with 1.75? 1.75 is much easier to work with and I could do it with the 6.31 MED. 1.8 requires the 6.4 MED and I don't know how compatible it is with the 6.31 MED and earlier.

Anyway, I'm sleepy at the moment so I'll make your model (if you want it) when I wake up about 11 or so hours later....