Edward T,
Echo's my sentiments and help the customer tech, not every nut and bolt comes out the back of your van to get the job away and that tech may have one in his workshop, not only that you may need a lift out with an arkward drive or hoist motor he will be the man to help you so why alienate him, also I bet your parts department is not complaining about the parts there selling to this customer, one way or another your company wins so go with flow and keep the customer happy.

Regards Titus