I don't know the answer without doing some searching, but here are a few ideas.
3D has really jumped into the market. On the Shapeways site there are lots of C-130 props in various scales, although they do tend to be the newer six and eight bladed ones.
One maker on there is a guy named Curtis. You should email him. Usually you can get a product that they have the design files for in other scales.
When I built my 1/72 Hercules, I had the same problem. I ended up buying a cheap partially built P-3 on eBay for the props. But I don't think there are any of those around in 1/48. Good luck.
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