Depot Repair - Where product sold to X and Y came for repair.

Hello Experts,We require help on the have following scenario in Depot Repair and Install Base  - 

We have sold an item (Serial Controlled) to X customer.

Then X sold this item to Y customer.

But now the Y came to us for repair of the item sold to X.

when we create SR through Depot Repair we need to specify the customer name and it will be 'X' as the Install base contains the item by 'X' customer's name.

Since the Y customer has given us the order for repair and if we book Repair order using the Y customer the Item is not accessible in the Depot Repair module.