Well tried a 17mm brake pipe spanner, thinking that the thickness of the wall would grip the maximum amount of the bolt and it still slipped as 17mm normal spanner also slipped
Tried to get mole grips on as there really were no flats/corners left...couldn't get the angle, so was thinking sump off at this point, so set about the exhaust... came off a doddle, even though the bolts looked a bit suspect and soft
Mole grips back on at a far better angle and on tighter than a tight thing, tap, tap tap with the hammer and IT MOVED!!!!
Was a bit late at this point, so changing engine oil is postponed until tomorrow, rather than warm the engine up with the exhaust off too late...will also keep it locked in the hut...
Happy bunny again.
Now how whether to get the neck of the exhaust welded or pack with exhaust paste and clamp it ... dying to go for a decent run on it this weekend, so know what I am swaying towards...