whats all this then, dangerous stems never, Mafac's that DON'T work...never, seiously though I have had and used plenty of these 'death' stems and I am still here, I think it all depends on the condition of the stem and its useage, anything with a crack bin it! or display it/them all on a framed board. many of these early stems were sand cast but are indeed works of art and if used as most of us really do ie plodding /riding gently there should be no problem...but ridden like a bat out of hell on a track ...well life expectancy about ten minutes...as for Mafacs when set up properly with decent blocks in, you can stand a bike on its nose with them....anybody go an alloy caged TANK left pedal, French thread with steel end cap,? the cage on mine has cracked ,the cage top has 2 steel? grip stips on top and bottom similar to a Phillips alloy pedal from the 50's.
Steve Chambers
Chesterfield
England...