I'd think you might want oxy-acetylene to get serious heat into the metal but if you don't really care about the inside appearance, just bog up with dent with body filler and be done with it. You could faff around with a panel beater to get a better internal finish but in the end what does it matter?
I think it looks pretty cool as it is but then that's just me!...
Well after considering the options went ahead today and gave removing the dents a go. Nothing really to lose and the post war paint doesn't matter anyway. Pleased to pass on that cold working with a high tech arrangement of a dowel, concave block using a mallet worked very well. Took about 10 minutes of careful but assertive tapping and it turned out great. The two smaller dents popped out perfectly and the larger one has only a very slight ripple that a smear of filler will conceal, very happy and ready for the next step. First pic shows the helmet prior to repair with two previously restored Quist helmets. From left Q68 M35, Q66 M40 and the Q64 M42.
Very cool shell! Could you by chance post any pics of the batch number and size, Just curious as it is a Q M42
Btw, this lot number DN541 is in Brian Ice's book .
Two are listed, both black. One police, one fire. Wonder what yours was?
He says mid 1944 production.
" When you're chewing on life's gristle, don't grumble, give a whistle "
Thanks for that info, I used to have a PDF copy of Brian Ice's book before my computer crashed horribly last year. I discovered my restored M35 was indeed most likely a DD Heer which was spooky as that's how I finished it and the M40 was non decaled Heer/SS, I gave that one an adler. Interesting the documented helmets were painted black however I'm pretty sure this is good old Czech reissue fire/police paint on the 42. Will most likely finish this lid in textured late war dark green unless I become inspired to do otherwise.