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 Medium Alt Build Medium Builds Spyrius Spyrius Alternate Builds 

6939 – Back B

February 5, 2023February 13, 2023 Master Builder 5616 Views

From: 6939: Saucer Centurion
Name: Spy-star Defender 1
Instructions: View PDF | Download .io File

Contributions

  1. Name, PDF and .io file submitted on February 5, 2023 by: Valdis
  • ← 6939 – Back A
  • 6939 – Back C →

You May Also Like

6736 – Back B

April 7, 2026April 22, 2026 Master Builder

1687 – Back D

January 25, 2022January 25, 2022 Master Builder

885 – Back C

January 27, 2024May 13, 2026 Master Builder

6539 – Back C

October 26, 2026October 26, 2026 Master Builder

6883 – Back D

November 21, 2023December 3, 2023 Master Builder

6503 – Back C

July 9, 2022July 9, 2022 Master Builder

EXPLORE MORE OFFICIAL SETS

6047: Traitor Transport
Castle Castle Sets Fright Knights Medium Builds Official Sets 

6047: Traitor Transport

November 18, 2021November 18, 2021 Master Builder

Year Released: 1997BricklinkInstructions

6941: Battrax
Blacktron Blacktron Sets Box Marketing Blurb Large Builds Official Sets 

6941: Battrax

September 13, 2019March 28, 2026 Master Builder
6539: Victory Cup Racers
Extra Large Builds Official Sets Race Town Town Sets 

6539: Victory Cup Racers

October 26, 2026October 26, 2026 Master Builder
6901: Mobile Lab
Classic Space Classic Space Sets Medium Builds Official Sets Space 

6901: Mobile Lab

September 11, 2020August 4, 2023 Master Builder
6896: Celestial Forager
ABCs Jørn Thomsen M:Tron M:Tron Sets Official Sets Small Builds Space 

6896: Celestial Forager

January 26, 2022July 31, 2023 Master Builder
6548: Octan Gas Station
Gas Station Medium Builds Official Sets Town Town Jr Town Sets 

6548: Octan Gas Station

October 12, 2021October 12, 2021 Master Builder
1723: Castle / Pirates Combi Pack
Bonus/Value Packs Castle Castle Sets Dragon Knights Imperial Guards Official Sets Pirates Pirates I Pirates Sets Small Builds 

1723: Castle / Pirates Combi Pack

March 30, 2026March 30, 2026 Master Builder
6879: Blizzard Baron
Ice Planet 2002 Ice Planet 2002 Sets Official Sets Small Builds Space 

6879: Blizzard Baron

November 20, 2019July 29, 2023 Master Builder
6462: Res-Q Helicopter
Medium Builds Official Sets Res-Q Town Town Sets 

6462: Res-Q Helicopter

July 10, 2026July 10, 2026 Master Builder
1732 (1712): Crossbow Cart
Castle Castle Sets Dragon Knights Official Sets Very Small Builds 

1732 (1712): Crossbow Cart

August 19, 2024October 8, 2024 Master Builder
2845: Indian Chief
Indians Official Sets Very Small Builds Western Western Sets 

2845: Indian Chief

October 10, 2023October 10, 2023 Master Builder
4726: Quidditch Practice
Chamber of Secrets Harry Potter Harry Potter Sets Medium Builds Official Sets 

4726: Quidditch Practice

February 27, 2023February 27, 2023 Master Builder
6930: Space Supply Station
Classic Space Classic Space Sets Medium Builds Official Sets 

6930: Space Supply Station

September 13, 2019September 11, 2023 Master Builder
4532: Manual Level Crossing
9V Medium Builds Official Sets Town Train Train Sets 

4532: Manual Level Crossing

May 22, 2026May 22, 2026 Master Builder
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
6874: Moon Rover
Classic Space Classic Space Sets Official Sets Small Builds Space 

6874: Moon Rover

November 6, 2023November 6, 2023 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.