Been to halfords this morning...
Shopping list consisted of the following..
2x Cans of Underseal (might have to remove the plastic lining inside the arch!)
1x Can of NO MORE NAILS (to bond G60 arches back onto the body)
1x can of NO MORE SEAL GUNS (to seal the aches so no water gets behind)
1x Small can of silver Hamerite (to seal the cut arch, dont want any rust!)
1x Paint brush (to paint on the hamerite

)
Just gotta borrow an angle grinder now.. and wait for the G60 aches to arrive.
Might get the camera out and do a step by step tutorail..
KnobbY!