More Destroy stuff

code/modules/assembly/assembly.dm

@@ -62,6 +62,14 @@
 			process_cooldown()
 		return 1
 
+	Destroy()
+		if(istype(src.loc, /obj/item/device/assembly_holder) || istype(holder))
+			var/obj/item/device/assembly_holder/A = src.loc
+			if(A.a_left == src)
+				A.a_left = null
+			else if(A.a_right == src)
+				A.a_right = null
+			src.holder = null
 
 	pulsed(var/radio = 0)
 		if(holder && (wires & WIRE_RECEIVE))

code/modules/assembly/holder.dm

@@ -24,6 +24,12 @@
 	IsAssemblyHolder()
 		return 1
 
+	Destroy()
+		if(a_left)
+			a_left.holder = null
+		if(a_right)
+			a_right.holder = null
+		..()
 
 	attach(var/obj/item/device/D, var/obj/item/device/D2, var/mob/user)
 		if((!D)||(!D2))	return 0