>>4090717A lot of cameras were made with discrete electronics. For example, the circuitry in this olympus is fully repairable. In the worst case scenario, you would lose working auto-exposure forever, because that's all its for, but the camera could be made to function manually even if the light meter's sensors failed (and were replaced so the circuit got a fixed readout all the time). Discrete electronics were pretty common up through the 80s. Even if the board itself is damaged a replacement can be etched and assembled from parts salvaged off the old one and new stock.
But if it uses ICs, or any one-off parts, if those ICs are out of stock you're boned and either lose what they controlled or the cameras functionality, period.