Some ideas to make it easier to remove the top
Post in thread 'Tornado takes the top off 1964 SWB FJ-45' Tornado takes the top off 1964 SWB FJ-45 - https://forum.ih8mud.com/threads/tornado-takes-the-top-off-1964-swb-fj-45.522904/post-14184433
And to answer your question on the windshield secure...