Shapeways 3D printed stainless steel is very strong and rigid with similar properties to 420 stainless steel, except it is infused with a bronze content of up to 30%. It has a slightly pitted surface finish for that vintage look.
Have a look at the 'Material Overview' and the 'Design Guidelines' if you want to make that sword hilt. http://www.shapeways.com/materials/steel
My main issue is that I would not be able to run it through the paces of my normal antique patination... as the stainless would be impervious to the acids that I use. But I can give it a shot with one and see how many 'years' I can put on one.
Bathsheba-Bob says give it a try. I don't know jack about metallurgy, but I've seen this metal rust...I don't think it comes out of the printer as stainless as it went in.-Bathsheba