I have ran across a few end user parts changer myself. Most large customers have several different types and configurations of trucks. Some are really great on repairs of the make mostly used while the more specialized or less used equipment kinda fall way side of wanting to be worked on. Usually when they do get "repaired", we get a call. I have a great customer base and most if not all value my opinions on different aspects of what kind of equipment is needed and what would work best in the application in which they are wanting a truck for and repair options. The way i approach the customer and to keep their employee/parts changer out of hot water is get with the repair supervisor and explain that your mechs can't will them all and it might be a cost advantage to let us do the repairs on the " not so popular " units. On the trucks mostly used i drop a hint to let the parts changer watch the sharper knife in the drawer troubleshoot. I also explain that the outside mech has more resources and contacts that can diagnose the problem than the inside man. I don't cover the parts changers rearends but i do put it in the supervisors head the the equipment may be beyond the scope of the average one brand/one system repair guy. For example i have seen where the inhouse/employee can sharp shoot a reachtruck with all bells and whistles but can be blown out of the water with a simple Curtis set up in a pallet jack. It all boils down to letting the man in charge know that overall he has a good crew and in time the mechs will get more familiar with the equipment. In the mean time let the super know that with more modern higher tech trucks and without brand specific training for his/her employees that you are there to take up the slack.