No question this copy was used in a shop. Interior soiled throughout, previous owners' names written in ink to the title page, some greasy finger prints. Corners are dog-eared, short tears here and there. Card covers (softcover) are soiled and chipped to the corners, previous owners name in ink to front wrap. Detailed break out illustrations and parts lists. Scarce in any condition. 5th edition published in November, 1945.