With the current settings on 30m (26cm 2.5 turns shorted), fc on 40 shifted to 7.188 MHz – even with 8 turns shorted. Moving the shorting strap to 7 turns, fc shifts to 6.988 MHz. With 7.5 turns shorted fc = 7.039 MHz.
L40=26cm 8t fc=7.166M
|L40=26cm 7t fc=6.988M||L40=26cm 7t5 fc=6.988M|
Unfortunately, this influenced the 30 meter band as well shifting the resonance down, but still SWR below 1.5 within 10.100-10.150 MHz. No influence on 15.
FYI, an index of all SWR graphs can be found here.