In case anyone still cares about this, I have completed my bottom stripping.
I tried chemicals, no good (I think it was too cold). I tried scrapers. The scrapers worked, but it was VERY slow going.
So I gave up and hired a soda blasting guy. For $1700 he did a great job.
Some pics are here:
I need to do a little sanding, clean up the keep, then barrier coat and paint
IMHO, the price was well worth it.