So now I need to put a tube in the centre that will hold a standard sized  tube.

I am going to straight up say I could have sculpted, molded, and cast this by now. Not because sculpting by hand is easier, but because I have enough experience in that to know exactly what I;m doing at every stage I can accurately mark and cut with a high degree of precision when I want to. But I wanted to do something that I wouldn’t have to keep exposing myself to toxins for replacement parts

But I did get obsessed and am really paying for it in terms of pain and fatigue!