Heidelberg Castle VS Shackles of Enkidu

Can Heidelberg Castle be used to move a set of Shackles played by someone else on your minion?

e.g. Minion A moves the Shackles pre-range to Minion B1. Can B1's controller use the Castle to move the Shackles to Minion B2?

Name: Shackles of Enkidu
[DS:U]
Cardtype: Equipment
Clan: Gangrel
Cost: 2 pool
Unique equipment.
Before range is chosen in a round of combat, you may put the Shackles on any minion opposing the vampire with this card; you still controls this card, however. Combat ends. The Shackled minion does not untap as normal during his or her untap phases; he or she burns 2 blood during each of your untap phases. Any minion may burn this card as a action.
Artist: Michael Weaver

Name: Heidelberg Castle, Germany
[DS:U2, FN:PR, KMW:PAl, LoB:PI]
Cardtype: Master
Cost: 2 pool
Master: unique location.
Tap to move blood, equipment cards and/or retainers between any two ready vampires you control. (You choose the amount of blood you move and which cards you transfer.) Cannot be used during an action.
Artist: L. A. Williams

the1andonlime wrote:

Can Heidelberg Castle be used to move a set of Shackles played by someone else on your minion?

e.g. Minion A moves the Shackles pre-range to Minion B1. Can B1's controller use the Castle to move the Shackles to Minion B2?

Not during that combat or during that action (per Heidelberg's restriction), but otherwise, yes. The Shackles are an equipment that can be moved with Heidelberg.
In your example, the "Shackled minion" would be B2, after the move.

Name: Shackles of Enkidu
[DS:U]
Cardtype: Equipment
Clan: Gangrel
Cost: 2 pool
Unique equipment.
Before range is chosen in a round of combat, you may put the Shackles on any minion opposing the vampire with this card; you still controls this card, however. Combat ends. The Shackled minion does not untap as normal during his or her untap phases; he or she burns 2 blood during each of your untap phases. Any minion may burn this card as a action.
Artist: Michael Weaver

Name: Heidelberg Castle, Germany
[DS:U2, FN:PR, KMW:PAl, LoB:PI]
Cardtype: Master
Cost: 2 pool
Master: unique location.
Tap to move blood, equipment cards and/or retainers between any two ready vampires you control. (You choose the amount of blood you move and which cards you transfer.) Cannot be used during an action.
Artist: L. A. Williams