Typical common and cheap drum brake systems don't use a cast alloy "spider" like that shown in the linked page for this car; they use a stamped steel brake backing plate (usually purchased as a "loaded" assembly complete with slave cylinder, shoes, springs, and other hardware bits.
The only thing close to "standardization" is that a small number of bolt hole patterns are used for common trailer axles. Most trailer brakes are electric (which are not sufficient for a motor vehicle), but hydraulic trailer brakes are readily available. If you are remarkably lucky, one of those trailer assemblies might fit. If you are just lucky, one of them might fit by drilling new mounting holes.
For better brakes, replace the "spider" with a bracket to hold a caliper... and fit a disk (instead of drum) to the hub. That could be a lot of work.
The only thing close to "standardization" is that a small number of bolt hole patterns are used for common trailer axles. Most trailer brakes are electric (which are not sufficient for a motor vehicle), but hydraulic trailer brakes are readily available. If you are remarkably lucky, one of those trailer assemblies might fit. If you are just lucky, one of them might fit by drilling new mounting holes.
For better brakes, replace the "spider" with a bracket to hold a caliper... and fit a disk (instead of drum) to the hub. That could be a lot of work.
