Removing... et c... The final challenge: Stuck seatpost

[classic33]

View attachment 826538

Todays attempt to mechanically remove the seat post: I dosed it liberally with penetrating oil and attacked the post itself with cold rust remover.

It broke the screw as seen, then moved the table.

Next time I'm in town I'll be getting the drain cleaner for very, very careful application when I next have the workshop to myself.

Is that a "V" in the centre of the jaw face?
You want to keep the seat post as close as possible to the centreline of the vice.