Help me out Oppo. On my nice new old trailer, the rear propstands are completely seized.

I've let them soak in WD40 for one night, Tri-flow the next night, then stuck them in the vice and tried a 2lb hammer and 4lb maul. No shifty shifty. There's no visible rust on any of the thread or on the collet.

Today I've tried heat and a breaker bar and still no movement. What are my next steps short of leaving them on for decorative purposes?