Grundy (G style) keg for reuse

[Portreath]

I mentioned way back that I've come in to ownership (legally) of a few kegs when my wife took over a restaurant. We got rid of the pile of kegs out back, by leaving them out for the dray that delivers to the pub next door, but no one would take the little 30ltr keg. So I'm going try to use it in my kegerator. I've released all of the pressure from it by hooking it up to the faucet/beer tap without any gas connected and seems empty to me. Do anyone have any-idea if the G type fitting can taken of, so the keg can be, cleaned filled and reused?