The Chipmunk was designed by Wsiewolod Jakimuik who was also heavily involved in the Mosquito project, so similarities are not accidental. Jakimuik escaped Poland during the German WW2 invasion and after the War went to Canada where he also designed the Beaver.
lelalo - I have some documents from my time as a RAF QFI on the Chippy, including the Student Study Guide. PM me with a snail mail address and I will send you a copy.