Well, it has been quite a wait, but the cases are finally welded.
Unfortunately, because my former welder had to give up his business due to health reasons, I spent quite some time searching for another laser welder. The toolmaking company I finally found said they'd give it a go, even though they had no former experience with engine casings. I stressed the importance that they remain straight and declared they had all the time they might need. Over the past months, I could see slow progress being made when I delivered and collected other stuff to be repaired, things were looking promising. Anyway, the long-awaited call came Friday, I picked the caboodle up this morning.
Welds now need dressing, stud thread is to be bored and tapped, oil passage re-opened, cylinder base surface re-faced and then it will be ready for a blast with glass beads. I'm quite confident the end result will be OK. The repair will not become entire invisible, but imo, quite acceptable. Old racing bangers have always been repaired as circumstances require, I'll let it carry its scars in dignity.
I'll see how it goes in a couple of days.
piet