Need help with rusted shuttle cover on badged National
I have a badged National head that I posted a picture of, over on "can this machine be rescued". The sliding cover to the shuttle race is rusted shut. I think it's mainly at the outside edge of the machine. I'm trying lubricating oil and I do have some stronger rust remover. I suspect this is a somewhat fragile piece, so I'm reluctant to try using a screw driver to wedge those two covers open. Am I on the right track with the fluids, or is there anything else I can try?