two problems I see right offhand are..
first, the factory roll marks are going to right at the end of the barrel. looking kinda out of place & off-centered..
second, and more importandly... are you going to have the barrel renickeled afterwards?
the cutting & crowning are going to expose the "raw" steel under the nickel, and theres a color differance between the two..
My personal choice would be to find a 3-1/2 or 4 inch nickel barrel and just have it rebarreled rather than cutting & crowning