Other than taking an ignition wrench and grinding it down, does anybody have
a source for stamped thin metal wrenches?

Try a bike shop. I have a couple of thin wrenches that I picked up in
conjunction with biking - though I don't recall the reason why those
particular ones were chosen (maybe they were cheap). The ones I have
are metric - inch equivalents may not be readily available. OTOH I have
often used the closest metric size on inch-size nuts (whatever I can
lay my hand on first).

Dave Johnson