I've made a new former #3 and carved out the hole for the pushrods. I deviated from the instructions in that I've joined the fuse halves together with the formers instead of glueing the formers to the top block and then bringing the fuse sides together.
I've also mocked my engine and mount together and determined that the firewall had to go back about 3/16. I wanted to side mount the engine so the pipe exited under the plane, but with 2 deg down thrust, the pipe would be angled up into the wing.

Once the firewall cures I'll add the top blocks. I might wait to add the bottom block unil I get pushrods installed.