I have used EasyOff oven cleaner to strip paint from a 30's automobile trunk, it worked very well; right down to the base metal, which is what I wanted. spray it on, let it sit for a few hours and hose it off.
I had read that one could use CLR to clean off a 1928 license plate. I made up a small tray of tinfoil, poured it on the plate and let it set for a couple of hours and it took the paint right down to the base metal as well. That was NOT what I wanted.
I might be tempted to try EasyOff, but watch it closely and not let it sit too long.