Ben , I have 2 kits waiting for me to put them together & it doesn't look likely anytime soon. You are correct about the music sound frames , holding between your fingers they are bare Audible , mount it to a thin metal base and they can easily be heard across the room.
If my memory is correct, one of your kits is the oil derrick? That one is on my wanted list and it's not pricey but I only have so much free time so I will only put it in my cart if I find a screaming deal. If I had a lathe at home, I would probably be making pulleys and Jack shafts and Baker fans. I am on the hunt for a nice South Bend lathe or similar...but I do enjoy the woods kits to....specially if it is something I can belt up to an engine.
Yes , I built the Wilesco oil Derrick kit (D11) & then modified it heavily , the kit stock is a poorly thought out imitation of a working oil Derrick , as designed the engine has to run at as close to stall speed as its capable of , & the oil Derrick arm will still be rocking at radical ,very unrealistic speed , it must be geared down to have any semblance of normalcy.