"I doubt he was an elder at 19." - Fulano
It depends on the time and the circumstances. Nowadays I believe it would be impossible, but I don't know for sure since I have been out of the loop for years. When I was 17 years old back in the Winter of 1972-1973, the congregation I moved into ( to serve where the need is great) had only 2 Ministerial Servants and no Elders. The Circuit Overseer contacted the Service Department and asked if I could be appointed a Ministerial Servant right away. They agreed that it would be OK to do so. (I wasn't appointed because I didn't stay in the congregation) Then the Circuit Overseer asked if I could be appointed an Elder before I turned 20 years old and the Service department said that it was possible but that the appointment would have to be approved directly by the Governing Body. As you probably remember, Fulano, things were much different pre-1975.