I don’t have a lathe either, all my stuff is made by hand so there is always hope :smiley: .
I get a lot of material from *bay, usually small cuttings of bar stock and tube. Solid bars are often very close to their stated dimensions, the tubes can differ somewhat but best to look for the seamless tubes and with a bit of luck you will get a close fit. I solder pieces together or use JB Weld where applicable.
Lots of filing & sanding is often needed.