greetings gang, just enlisted. guidance required on above topic. had these two shells in garage for ages.
As you can see the shells differ in shape.the rear part of the crown comb also differs between the two, the end of the comb on the left shell has a pointed end whilst the shell on the right has a rounded blunter end.the securing rivets are domed on the left shell, flat on the right shell. the shell on the left has an inkstamp ? NICROMAC. both do not have badge plates, so no clues there. Thus, does the shape indicate manufacturer variation, timeline or country or...............any info will be greatly appreciated, thanks chaps