Skip to content
Back of the Box Builds

Back of the Box Builds

LEGO Alternate Builds!

  • SETS
    • Adventurers
    • Aquazone
    • Belville
    • BATMAN™
    • BIONICLE
    • Building Set with People
    • Castle
    • Duplo
    • Fabuland
    • Harry Potter
    • Holiday and Event
    • LEGOLAND
    • Model Team
    • Pirates
    • Space
    • Star Wars
    • Technic
    • Train
    • Town
    • Universal Building Set
    • Western
    • More Sets
    • Misc
  • USEFUL LINKS
    • Submit Instructions!
    • New Instructions
    • New Official Sets
    • New Alternate Builds
    • Minifigs
    • Very Small Builds
    • Small Builds
    • Medium Builds
    • Large Builds
    • Extra Large Builds
    • How BOTBB was Built
  • THIS IS AN INDEPENDENT SITE NOT AUTHORIZED OR SPONSORED BY THE LEGO GROUP
Alternate Builds Instructions Added Large Alt Build Large Builds Model Team Model Team Alternate Builds 

5521 – Back A

January 29, 2026March 4, 2026 Master Builder 4595 Views

From: 5521: Sea Jet
Name: TBD 1
Instructions: View PDF | Download .io File

Contributions

  1. Name, PDF and .io file submitted on January 29, 2026 by: livi
  • ← Space Skeletal Horse Concept
  • 5581 – Back A →

You May Also Like

Book 7777 – Page 8-9

March 23, 2023August 1, 2023 Master Builder

5928 – Back A

February 22, 2023February 22, 2023 Master Builder

6542 – Back C

November 20, 2023November 29, 2023 Master Builder

6875 – Back B

September 16, 2019March 14, 2025 Master Builder

6896 – Back A

January 26, 2022January 26, 2022 Master Builder

6397 – Back E

August 18, 2022May 17, 2023 Master Builder

EXPLORE MORE OFFICIAL SETS

6473: Res-Q Hovercraft
Large Builds Official Sets Res-Q Town Town Sets 

6473: Res-Q Hovercraft

January 20, 2022January 20, 2022 Master Builder

Year Released: 1998BricklinkInstructions

6087: Witch’s Magic Manor
Castle Castle Sets Fright Knights Large Builds Official Sets 

6087: Witch’s Magic Manor

July 8, 2022July 8, 2022 Master Builder
1491: Dual Defender
Black Knights Castle Castle Sets Official Sets Small Builds 

1491: Dual Defender

October 11, 2021October 11, 2021 Master Builder
371-3: Seaplane
Airport LEGOLAND Medium Builds Official Sets 

371-3: Seaplane

October 8, 2024October 8, 2024 Master Builder
4818: Dragon Rider
Castle Castle Sets Knights Kingdom I Official Sets Small Builds 

4818: Dragon Rider

October 8, 2024October 8, 2024 Master Builder
6675: Road & Trail 4×4
Classic Town Off-Road Official Sets Small Builds Town Town Sets 

6675: Road & Trail 4×4

March 20, 2023March 20, 2023 Master Builder
6848: Strategic Pursuer
Bjarne Tveskov Duplicate Set Number Futron Sets Futuron Official Sets Small Builds Space 

6848: Strategic Pursuer

April 16, 2021March 11, 2024 Master Builder
6257: Castaway’s Raft
Niels Milan Pedersen Official Sets Pirates Pirates I Pirates Sets Small Builds 

6257: Castaway’s Raft

June 6, 2022July 29, 2023 Master Builder
1704: {Unknown – Ice Planet Satellite Plow ?}
Bonus/Value Pack Sets Classic Town Fire Ice Planet 2002 Ice Planet 2002 Sets Official Sets Small Builds Space Town 

1704: {Unknown – Ice Planet Satellite Plow ?}

September 6, 2023September 7, 2023 Master Builder
6761: Bandit’s Secret Hide-Out
Box Story Cowboys Jørn Thomsen Large Builds Official Sets Western Western Sets 

6761: Bandit’s Secret Hide-Out

December 29, 2021April 3, 2024 Master Builder
1096: Race Buggy
Classic Town Official Sets Race Town Town Sets Very Small Builds 

1096: Race Buggy

July 26, 2020July 26, 2020 Master Builder
6378: Service Station
Classic Town Extra Large Builds Gas Station Official Sets Town Town Sets Wrecker 

6378: Service Station

February 25, 2023February 26, 2023 Master Builder
6828: Twin-Winged Spoiler
Futron Sets Futuron Official Sets Small Builds Space 

6828: Twin-Winged Spoiler

November 20, 2019May 25, 2020 Master Builder
6769: Fort Legoredo
Extra Large Builds Jørn Thomsen Official Sets Western Western Sets 

6769: Fort Legoredo

November 10, 2019July 29, 2023 Master Builder
1509: Town Value Pack
Bonus/Value Pack Sets Bonus/Value Packs Official Sets Race Small Builds Town 

1509: Town Value Pack

October 8, 2024October 8, 2024 Master Builder
8957: Mine Mech
Official Sets Power Miners Power Miners Sets Small Builds 

8957: Mine Mech

March 27, 2026March 27, 2026 Master Builder

BOXES

INSTRUCTIONS

FAVORITES

MINIFIGS

About This Site

Logo
There were once pictures of additional LEGO® builds on the back of set boxes. Written on the boxes was typically something about the endless building possibilities, "Build any of these exciting models with this set!" There were no instructions for these alternate builds, until now.

Sets

  • Adventurers
  • Aquazone
  • BATMAN
  • Bionicle
  • Belville
  • Building Set with People
  • Castle
  • Duplo
  • Fabuland
  • Harry Potter
  • Holiday and Event
  • LEGOLAND
  • Model Team
  • Pirates
  • Space
  • Star Wars
  • Technic
  • Train
  • Town
  • Universal Building Set
  • Western
  • More Sets
  • Misc

Useful Links

  • Submit Instructions!
  • New Instructions
  • New Official Sets
  • New Alternate Builds
  • Minifigs
  • Very Small Builds (<35 pcs)
  • Small Builds (<100 pcs)
  • Medium Builds (<200 pcs)
  • Large Builds (<400 pcs)
  • Extra Large Builds (>400 pcs)
  • How BOTBB was Built

In Honor of 1526

The classic space set that never was.

Copyright © 2026 Back of the Box Builds. All rights reserved. LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize, or endorse this site.