I certainly recognize this...
You might get rust between the plates and the subframe though...
There is an alternative; the jack block (although it requires more effort to make): https://www.theminif...hl=+jack +block
Certainly liking all of the steps you're taking , although the reason to do so is terrible
Keep it up!
The way to stop rust forming is to weld the plate on
Then force Electrox zinc primer in the seam
I will seam seal around the join when the electrox is dry. The electrox will sacrifice itself to stop the steel corroding. In doing so it will use up the oxygen in the void. If I seal it properly, no oxygen means no rust. That's the science behind it anyway.....
The wooden blocks look good if you have a concourse car, but this build definitely isn't and it's easy to just roll the jack under and away we go.
Pete