Who currently produce components that go into Teslas.

I was originally looking for "old companies that currently work in tech", but even their original industry of copper smelting was pretty high tech for the 15th century.

Maybe let's do it in two classes: oldest information-managing tech company and oldest mechanical tech company?

If you consider banking to be information-managing tech (which it seems to me that it is), then the oldest may be either Berenberg Bank (1590) or Banca Monte dei Paschi di Siena (1472). It depends on the definition of "bank". The later is certainly a bank now, but was more like a pawnbroker in its early years.

I mean, I don't know what other definition you want.