Engine mount rod?

I had a great day today spent disassembling my kz750. I was trying to remove the exhaust but I got stuck on a bolt.
There is an aftermarket crashbar that was installed that I need to remove in order to free up space to get the header out. This crashbar is mounted onto the bottom-front of the frame.
The bolts on both side are connected by a single rod with threaded ends. I managed to free the right side bolt but the one on the left side is completely seized.


www.cmsnl.com/kawasaki-1980-kz750-e1_mod.../partslist/9547.html
If you look at the frame fittings, it would be bolt 22 that I can't remove. I don't quite understand what #16 is, since I just have a rod going across that whole section.



Any tips for getting the bolt off? I have tried anti-rust, wd40, locking the other side with two bolts (the rod just spins through both), jamming things to stop torque...
The rod is really rusted, can I just tap it out, or should I jack the bike first because it's holding the engine? Where can I find a rod to replace it? Hardware store?

Thanks for the help!

The rod will go right across the front of the motor. There it is inside of a rubber motor mount, which has a metal sleeve. this is what it rusts to. Striking it flexes the rubber, but may free it. All thread cold be used to replace it, or Feebay would have the rod, or possibly a member here will speak up with one.

WD40 isn't going to do much. I'd soak it with Kroil for a couple days. It will free up. Ed

So can I just tap it out from the side without the bolt all the way through and find a replacement in a hardware store?
That would be ideal.