I don't wish to be rude, but the sill is a structural item and patching it up like that almost certainly will have weakened the car, thats why it appears to have bent, because it has! At the very least you should have braced the door openings and supported the car undeneath in the middle before removing the sill. You really should buy a replacement panel and replace the sill properly rather than butchering the old sill like that. To me that looks like a dangerous bodge that could lead to a catastrophic failure in the event of an accident or even in normal driving. Theres a reason that bodywork on cars like this gets neglected, its expensive to repair properly, you could be putting yours and other road users lives at risk by a poor repair like this.
the standard of welding in the thread has bugged people.
..on a painted surface, I find that I only need to score a line or two on the edge to be joined for the weld pool to do the rest, ie, blast away paint and crud to get at fusible metal underneath. Hence my laziness at surface prepping!
Wow, I never knew workspace was so difficult to find over there. Go West Young Men, Go West. Over here, most car guys have a huge garage with a small house attached to it...hehe. It's the American way...until the wife gets a hold of ya!
Yeah that woodburning stove Silas.....sounds good.