Some of these parts are available here: Land Cruiser 40 and 55 Series - https://www.cityracerllc.com/collections/land-cruiser-40-and-55-series
I've heard in some cases shop vac hoses have been used to replace those hoses.
'73 wouldn't have had a cage originally. I'd get a Metal-tech roll cage and enjoy having a safer cage. Stock cages are thin and won't take a hard roll.