In this step in t' assembly sequence o' t' Apogee Components 1/70th scale model o' t' Saturn 1B rocket, is where you'll be attachin' t' fin unit t' t' fuel tank sub-assembly. This step needs t' be done before installin' t' SIV-B/Interstage; so don’t skip this step. Avast, me proud beauty! Blimey! T' fit o' t' plastic transition over t' fuel tank tubes is very snug. So before intallation, it will be necessary t' remove any paint from inside t' plastic transition.