Joe ... Great question. While the internal/mating portions of the safety lever and decocker lever appear very similar, I haven't a clue if they are interchangeable. Your best bet on this one is an email or a call to Ruger (I'd be interested to hear their response).
Search for after market options and if that doesn't work find a good TIG welder and have a tab welded to the right side decocker. A little work with a hand file, sandpaper, cold blue can produce wonders.