And there Kenny you have hit the nail on the head. We like to build to scale but sometimes we just have to get close because of strength limitations.
Your boom which looks good as it is, would in reality have to be constructed from plasticard of 0.17mm, that is, 1/10th of a mm to be the thickness of plate steel (1/2inch)
I have some plasticard of this thickness and it is like tissue paper, you could read a newspaper through it, absolutely no use for an item like your boom.
For my handrails (still to be started) I bought a coil of 0.4mm brass wire, pull it tight and it will straighten out for use. Trouble is, it may be just about scale but is so fine it could be damaged by the slightest knock.