Guys you did it the hard way
I just used a reciprocating saw with a metal blade and had the whole lot done in about 1-2 hrs and stuff all mess
Cleaned up with a wire brush in the
OLD Black & Decker then got the whole frame sandblasted at my local slipway in the afternoon and had it undercoated in KBS Rustcoat etc in time for tea.
Pics to follow tomorrow
Rog