...hmmm....what about a Merou muzzle? If your pipe fits the Meroue handle, it will probably be ok for a muzzle of the same brand (Merou sells online at
Merou.it - Web Site, all very good quality gear, I'm told).
For the rail thing, don't worry if it's low: it is not mandatory for the spear to "touch" the rail when the guns is loaded: it will fall on the rail when you shoot due to the drag of the oblique bands.
Hope this helps
