An Achilles Heel…..IZH46M

[Frank in Fairfield]

It feels like it Mike and the new piston seal was due.
I can tell the compression is much stronger.
Chronograph will tell.

[Airnut]

Nice!
Depending on your welder's skill and the filler alloy he used that repair might be stronger than a factory new part.

Yes and no. The weld filler metal will be stronger but welding cast steel has a tendency to make the base metal brittle within the heat effected zone.
Without knowing what recipe was used to make the steel you can only guess as to what filler metal to use.
We will see if it will pass the test of time.(fingers crossed)