If your barrel is D&T'd for a scope rail, you could:
1-file or grind the rim of the hull to approximate fit of the barrel by wrapping the barrel with sandpaper, and stroking the hull back and forth until it matched the radius of the barrel.
2-use a punch or drill to make nice, clean holes in the bottom of the hull, to match the holes in the barrel that a scope rail would be mounted to.
3-with the fitted hull in place over the chamber, cut away just enough of the top of the hull so that you can mount the hull using some socket head cap screws, probably the ones intended for mounting the scope rail would do, washered up of course.
With a bit of paint, it probably wouldn't look bad, either.
I say go for it!