It's harder to get details of previous owners from the dealers due to the rules on data privacy. Most don't pass on the invoices or they blank out personal details. Always ask to see the V5 before you buy from a dealer as that will have the last owner address and the one before if it's at least 2 owners.
As Skint says, your V5 will show the name of the previous keeper, surely? Did you not get any service history (invoices/service book) when you bought the car? How did you work out it was supplied by Middlehurst? Who did you buy it from in Bradford? I appreciate you are just seeing if you can find the owner on this forum, but you must have some way of tracing it’s history? How about MOT records?