For my Deadzone Strike Team of Marauders i searched a way to play my Mawbeasts in both variants with a WYSIWYG style. So i cut the bomb from them, drilled a hole and sunk a steel nail in.
After that, i took some spare parts from my "Mauler" Rippersuits (the one from the Knockback CC Weapon) and sunk a 3x2mm magnet into them.
The Bombs were painted in a suitable paint scheme and of they go...BOOM!!