My most treasured kit is an unopened cargo ship from 1976...how hasn't this been opened in the last 44 years! I've managed to get the bricks to build a copy and then
LEGO 4000006 Production Kladno Campus | BrickEconomy
LEGO 4000001: Moulding Machines | Brickset: LEGO set guide and database
LEGO LOM Moulding (4000002-1) - Value and Price History - Brick Ranker
Rarities, oddities and retired LEGO sets up for auction