Hi Pete, and welcome to the forum.
The Zeiss are a classic, and if you don't need the very latest coatings and don't mind a slightly yellow tint, they will be a serviceable pair that will last many years.
If the binoculars don't have P* (phase) coating, it is likely that they will show some optical aberrations - I'd argue that the price is quite high though, check out these two for less (one heavily used, one good condition):
The London Camera Exchange supplies second hand cameras, new cameras, digital cameras and other camera equipment and provides a camera part exchange in photographic shops all over England, UK.
www.lcegroup.co.uk
CLASSIC ZEISS 10X40 BGATP JUST FULLY SERVICED BY ZEISS, SUPPLIED C/W CASE/SRAP AND RAINGUARD.
www.at-infocus.co.uk
If you are happy with used optics, here are three options that will offer better optical performance for less money:
As new condition New price £469
wessexphoto.com
The London Camera Exchange supplies second hand cameras, new cameras, digital cameras and other camera equipment and provides a camera part exchange in photographic shops all over England, UK.
www.lcegroup.co.uk
The London Camera Exchange supplies second hand cameras, new cameras, digital cameras and other camera equipment and provides a camera part exchange in photographic shops all over England, UK.
www.lcegroup.co.uk
It's worth noting that the Zeiss BGAT aren't technically waterproof, but it is worth remembering that they were used by birders for many years in challenging conditions with little/no issues.
Hope this helps!