Claude, you can see looking at the pipe how I epoxied some carbon roving around the pipe (at its CG) which locked in the nut that later would hold the Lord mount. The Lord isolator is simply screwed into the nut epoxied on the pipe. The pipe is carefully inserted into the belly of the model until the Lord screw hole is seen through the mounting hole in the fuse's belly.

The Lord isolator is secured to the airframe using a flat head screw from the outside of the model. The belly area is reinforced with a layer of 1/32" aircraft plywood to spread the load. Try it...it isn't tricky to set up and is so much more convenient to use. The main assumption is that the pipe length is known and will not be changed; if a change is wanted then some surgery will be required

Note also the bent orange coupler. This is the same coupler arrangement I have discussed before. It is custom molded using ceramic fabric and Permatex Ultra Copper sealant. Bends, dissimilar diameters, conical transitions, after mufflers, are all straight forward. Just need imagination