Personally, I would suggest you should just be teaching/demonstrating the what it takes to make this item. You can fabricate one, having the students each help with the milling or doing specific set technique. They should understand the basic milling part, you’ll be teaching how to use that skill to:
Square up a block:
… Have examples pre-made of each step, and show sequence.
Planning cutting sequence - considerations:
… Why cut angle, legs, or pockets in a certain sequence:
…vise pressures/deformation
… alignment issues
Choice of cutters sizes:
…Multiple passes vs single pass
… Surface finish and over-lapping cuts
…Cutter fluke length considerations with smaller diameter cutter:
…Smaller diameters, Flex and have less flute length
Special considerations for deep pockets
… Clearing chips out of slots and pockets based on cutter size
Setting up Angular cuts:
… Using sine bar,
… Precision angle
… Tilt table
At the end of the class they’ll understand and be able to set-up and do angular cuts, deep pockets/slots, work planning sequence, fixturing, cutter selection. They have their block of material to go do it.
You should be able to have 5 or 6 students in my opinion. I’m guessing you can do this in about 3 hours (the second time and beyond)