Finding a replacement for the indicator stalk on my Esprit was not possible, so I found an aftermarket switch used on a similar year car, which ended up being a Land Rover Series 3. The switch is identical to the original except that the connector pins are different, meaning you can’t connect it to the existing Esprit wire harness. More importantly, the actual stalk (or turn indicator arm) is bent the wrong way so it’s right up against the steering wheel. Both are pretty easy to fix. I ordered a set of Delphi GM 6 pin connectors and then re-wired the wire harness and the turn indicator to accept the same connector. Then, using a vice, I simply bent the stalk arm in the direction away from the steering wheel (carefully though as it seems like you can probably snap it in half if you go too far).
I picked up a new wiper arm switch, which is identical to a Triumph 2000, and then re-wired it using the same Delphi connectors I used for the turn indicator stalk.