So, coming back from No.1's coffee and putting kids to bed, I faced the both fuselages dry and ready for sanding and, on the other hand, both radiators in bad need of trimming and thinning to get appropriately into place
First the Berthold's plane: 1st pic shows everything prepared for work, and 2nd shows the meaning I used to fix the radiator to the fuselage. At that time I checked the fuselage-to-wings joint, and 3rd pic shows the obvious - wing has to be cut in half, and then the resulting hole shall require filling...
Rest of the pics shows that after the first round of sanding everything looks nice, although putty shall be required... Radiator now looks OK, that part is finished...