Maybe a bit of bronze would hold it enough or if your a creature of the times a spot of liquid nails! Carpet pythons are fine just big puppies really red bellies aren't much to worry about either. As a point of interest (maybe) the red bellies up your way (so I'm told) have white lips whereas down this way they don't and are more sought after by enthusiests. While talking about copper tube it can be bought chrome plated from the plumbing supplies. I was just looking at one of my axles and reckon it would take 5/8 copper to cover it. Either way, unless you can drive a vernier I would take the axle to be sure you get the right tube if your paying for it.