I cut rear cylinder mounts out of 1" A36 mild steel plate,I made sure to leave a good amount of metal around the cylinder mounting pin area so it won't get deformed again. I have them propped up in the photo here with some 1-1/4 rectangular tubing. The last rear cylinder plates were 1/2"thick steel and deformed under pressure because I didnt leave enough meat around them; I used what I had to build it. I'll tack these in place once aligned with MIG and then lay a root in with 120,000psi rod via TIG. I had to switch up to a 5/32 TIG tungsten for a bit more amperage capacity. The rear mountplates will tie into the 1-1/4"thick bottom sole plate. I might get time today to lay some root passes on the 2" front die plate as well.
I have to talk to a welder friend of mine about preheating all this as it's thicker plate than I usually deal with,so there may be some special considerations that have to be addressed.
I'm also aware of maybe some confined stresses with tacking it up first then putting all that heat into it with the finish weld process.
[Linked Image from kuhnbros.com]