Elna SU Air Electronic CI. 69 cabinet model ...Freearm??

I came across this website looking for sewing machine repair (or pre-repair) help. Maybe you can help me, maybe not, but I thought I'd give it a go.

I have an Elna SU Air Electronic CI. 69. It's the model designed to be installed in a sewing cabinet, desk, or table. The person I bought the machine from said that he had kept it in a cabinet, but it seems more like a barn or garage. There is some rust on the bottom. The cabinet freearm will not release. I figured out which bar pin in the mechanism is rusted in place, but can't get it to budge. I even tried tapping on the end of the bar pin (not the white release button) with a hammer hoping to maybe knock some of the rust loose, but to no avail. Should I oil or WD-40 the bar pin and try again? I can't see any where to disconnect the cabinet freearm as it appears to be designed as the bottom of the machine. Do you have any ideas or know of anyone who is familiar with this particular model? Any help would be much appreciated.

Thank You,
Kira Tucker