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):
Used Zeiss 10x40B T* Dialyt | 1018122 | London Camera Exchange - Guildford | To buy or for more information visit Guildford or call 01483 504040
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
Used Opticron 10x42 DBA VHD+ | London Camera Exchange - Bath | To buy or for more information visit Bath or call 01225 462234
www.lcegroup.co.uk
Used Hawke 10x42 Panorama ED | London Camera Exchange - Reading | To buy or for more information visit Reading or call 0118 9592149
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!