Hello - asking for some TDF wisdom.

I've a 21W Salvo HID that bought back around 2006. Apart from having a new cable and glands it's otherwise untouched. Still on the orginal bulb.

I've loved having it! However, the battery is kaput after getting it wet during diving this weekend. So - I'm debating whether to invest in a new battery, or perhaps put that money towards a more modern upgrade. I guess I could also realise some value from selling it, but without the battery.

So a couple of questions I suppose:

1) How does it perform relative to more modern unbilicals out there? In terms of brightness, durability and battery life. Does it's performance still stand up overall?

2) Any ideas on residual value? What's it worth if I got a replacement battery and sold it as working torch? What about without worry about the battery replacement?