Is there a source for parts to un-convert a 3 screw Blackhawk?

I recently picked up a 3 screw Blackhawk in 357, and of course it's been converted and did not come with the original parts. And the action and trigger rather suck. But it was cheap.
Now, I can work on an action, but before I tried to polish a turd, I didn't know if there is a source for original parts. Numrich is sold out, and I very seriously doubt Ruger will send me parts to make a gun "less safe" even if they do have them.

Now the obligatory picture. It came with some cheap plastic white aftermarket grips that are total garbage. I'm going to make a nice Walnut set.

sure. I have a local gunsmith who said he night have a lead on some original parts. If not, well, I'll polish as best I can. in the meantime, he said he has some original walnut grips I can have. I'm trying to decide if I should tear these bad grips apart to salvage the ferrules. If I do, then I'm down my grips until I get replacements.