I think it would be all custom. Just using proton bits would keep it in the same family.
Everything from handbrake cables being custom to the stub axles and caliper mounts. Then proton bits bolted on.
Other than the looks, wouldn't be much benefit. I have redrilled my drums to be 5x114. I do like the adjustable proportioning valve that the rear axle has, it puts more brakes to the rear when loaded, and blocks some pressure when it's got no load. This is worthwhile and effective