What did your original frame engine perches look like? Were they different vs what you have now? Your wagon is a '65 yes? What is the length of your original torsion bars?
I was where you are now with your stub about 2 months ago. What I would have done differently if I did it again was to test fit the rad support and front fenders now, vs when I built everything back (suspension and engine). Bolting the rad support in place and throwing the fenders on is easy, just to see if the fenders line up with the door. It tells you if you need the shims or not. I made new shims because mine were completely rusted, but it turns out I took out most of them to get the fenders to line up.
Also, now is a good time to thread the gas pipe through the stub rail.
What black paint did you use for the firewall?