221 Ideas Book No. 1 from 1973. In my experience their investigations take a couple of weeks.
Lego – 221 Ideas Book No. 1 – Vintage Book – Legoland theme – 1973
Vintage Lego brochure - Ideas Books 221 & 222 (1975)
Vintage 1973 LEGO Instructions Ideas Booklet 221 Number 1
LEGO 1973 Ideas Instructions Booklet Vintage 221
Lego 221 Instruction Manual - Book 1 - Building 1973 - Vintage - Good Condition
