As noted in earlier posts, most likely corrosion. Probably rust in
the cables due to lack of use and maintenance. Find something to spray
in the two cables.
WD-40, anything that claims to free rusted parts. Brake fluid if you
can get it in.
When you've got it clean keep it protected, especially as you live
where things go rusty. LPS-3 is my favorite rust inhibitor.
Jim