I agree with Ty. Do make it removable and adjustable. It has been about 35 years since I had the Super Combat Streak, but I just ordered plans from Barry Baxter to build another one. I liked it much better than the Flite Streak for the above mentioned reasons. A full body just cuts out a lot of inherent problems a Profile can have.
I don't remember exactly what the front end is like, but I will make a hatch for mine so that the tank can come out if needed. I never glue a tank in anymore.
As to the Nobler, I would make the cuts from the bottom of the fuselage, but you will probably have to end up cutting the top, too. When I make them "adjustable" when they were not originally done that way, I make a tank floor and slide the tank in. Then it can be held in place with "dense" foam rubber packed around it.