Wash basin Tap Spanner

[Alt Beer]

I need to replace the taps in the bathroom wash basin. There is a deep recess in the underside of the basin where the tap securing nut is located. The existing taps are OLD probably pre-metric. Looks like I need an open ended socket type spanner - does anyone know what size I need?

Thanks

[The Other Mike]

As I read this I half expected a parrot to appear but no, it's not Scotty, but there clearly must be something in the water up there.

[The Medway Handyman]

For a one off job you could try one of these

Their only benefit is that they are cheap though.

Much better is this type