Found this recently at a book and print shop.I always ..time permitting ..haunt these antiquarian book and print shops and idly search for any pyro bits. Found this in a sheaf of odd posters etc. I have in all my 60 years involved with Fireworks ..never ever seen this design...I believe it to be very unusual and rare.For a start ..never seen the spikes like these on any Brocks fireworks...or on any other for that matter!! Both fireworks portrayed here...once again I have never...ever..seen.Think it may have been produced as a speculative design study only. That said it has been used as a poster somewhere..tape marks at the corners etc etc.Curiouser and curiouser!...... Has anybody ever seen this or the fireworks portrayed?