Any question answered...

Mungo is 23.8mm, which narrows the choice quite a bit. Either a road drop-bar lever fixed to the bend of the bar, or a bar-end lever like a Tektro RX4.1 plugged into the end.

Thanks for the reply.
In terms of the bar end levers - it seems that people talk about:
RL720, RX 4.2, or TT200

So what's the rub? What's the big difference between them and which one is "best" or best suited for my cheap-ish alhonga deep drop brakes?