The bow in this case is consistent along the entire 7.6metre lengths of the steel when they arrived (more of a sag left to right if that makes sense, very subtle but needs to be levelled. The welding process has not accentuated this at all its not in twist intact its very straight as every joint and opposite joint was well held anddidnt really move much after welding due to the short periods of welding

The tacks then weld opposite is pretty much what I did but I did about a 30mm weld on one side then went back to the other then moved to the diagonal opposite part of the frame always checking then diagonals etc and angles for squareness so end result I am extremely happy!

Thanks for the comments :)