That illustration and information comes from a book about the 109 authored by William Green and entitled The Augsburg Eagle.
This was an attempt to design a heavy interceptor with outstanding performance utilizing as many standard 109 parts as possible in order to simplify production.
This was a concept that would have worked, had the decision been made to proceed with production. With a top speed of 462 mph it would have given the Luftwaffe an interceptor with 5 thirty millimetre cannon which would have posed insuperable problems for Allied fighter pilots escorting bomber streams over Germany.
Like the Me262, this is another one of those designs that raise the question "What if...?" for aviation buffs.
Regards, Shuckins
