Ryan - G8RKEOn the subject of EFHW antennas, I have found a really useful web based modelling tool. Been fiddling about with to try and get an idea of lengths etc.
Interesting that with my suspected poor gound conductivity, the harmonics aren't "lining up"
Using this tool it seems a 41.3m long element with 4m counterpoise and 4µH inductor 2m from feedpoint would give reasonable multi band operation, albeit with use of the radio matching unit.
In theory this could work as a reasonable multi band antenna.