I had just enough cutter length on the hole saw to get a clean cut completely through the frame tube.
Now I worked on removing the frame and getting setup to cut the opposite side.
I made the base plate so that I can swap on an adaptor bushing to locate the flip side. With two less frame tubes holding the head tube on I needed to rethink how I was going to stabilize the frame.
I started to bolt it back down through the head tube.
A few more jack screws along the top frame rails.
Indicate it back in like the other side. Looked plenty stable to me, let's give it a go.