Time to replace the front arches on Helga – once I started poking at the bubbles it was clear they needed replacing. Luckily Saabits offer weld-in replacement sections, and I’ve got a friend with a welder.
It’s not technically possible to get the front arches as repair panels – the trick is to buy rear ones but swap left to right. Still, I’m not sure why the curve of the new arch was quite a bit smaller radius than the arch we cut off because I’d read they’re supposed to be the same.
With the front edge of the left side lined up… 
and tacked in… 
the back edge is too short. 
So a filler piece was needed. I cut the repair panel a bit short.
Lots of small tacks to avoid distortion… 
Another patch under the washer bottle… 
Ground back… 
Primer… 
And a skim of filler
While my mate Rich was doing the welding I fitted a new water pump, thermostat, ECU temp sender and fan temp switch along with fresh red antifreeze. I’d already done the gauge temp sender and the radiator looks pretty new so that’s all of the cooling system overhauled. The old pump was binding at certain points and it was weeping slightly because the mounting face hadn’t been cleaned up properly last time. Hoping the temp sender helps the wonky running and the others are just for luck but it should all go towards better reliability once she’s back on the road.