I'm not going to down your rifle, but this kind of reminds me of the Geo Prism I saw in a man's yard for $6K. He had done all kinds of work to it (touted as being the most powerful 3 cylinder on the road) but in the end, it was still a $600 car. Admittedly, the absolute nicest Prism I had ever seen, with leather seats, slick paint job, and 20" spinners... But....
You could get 400, but I think your best bet would be to take it back to the stock configuration (except maybe the barrel, that may be more effort than it's worth) and sell it at a more consistent price for a used 10/22, and then try to sell the parts separate. That's just my opinion. I also know for a fact that there are people who would give you what your asking, or maybe try to talk you down about fifty bucks.
And to echo hi wall, best of luck to you. It's doable for the price your asking, but it may not be easy.