In the past Delivery Centers didn’t have any there. The Fremont DC had a small amount of t-shirts, jackets, coffee mugs etc. New buyers suggested they stock these at delivery locations and Tesla started doing this maybe just this quarter. Before that the NEMA 14-50s were part of the mobile charging kit.
In the past we decided to buy the corded mobile NEMA 14-50 connector to pretty much leave connected to our 14-50 outlet (avoid plugging in and out and causing wear) and was able to find one in stock at a Tesla Service Center. They said they only typically would stock one or two, but if people needed a 14-50 adapter and live near a Service Center worth a call I guess.