Boaters World sells Tigress and Perko's for less than $50 each. Just use some teflon tape on the threads of the nuts before you screw on and they won't loosen up at all. (And make sure to teflon tape the inner 'adjustment' hex bolt too!) Don't worry about a big fish. Seriously, unless you're setting your drag to 50# of pressure, the rod holder will not fail. Mine are 5 years old and working just fine.
I will say that the bolts have some pitting/corrosion on the heads, so its likely that they're either cheap neo-stainless or some other alloy. So you might consider new high-grade stainless bolts. Or else remember to take them off every other year so the bolts don't freeze.
I will say that the bolts have some pitting/corrosion on the heads, so its likely that they're either cheap neo-stainless or some other alloy. So you might consider new high-grade stainless bolts. Or else remember to take them off every other year so the bolts don't freeze.