Amazon search. 6 gun cabinet location London, but manufactured in China ,around 140.
No top box ammo, no thick door taking space, make sure dept is at least 25cm, to accommodate rifle scoped. Bin the bolts that come with it. Buy normal 3 inch length 8mm thick screws. Do your holes, vacuum dust, put plugs and the screw with metal washer inside. Vertically or horizontal doesn't matter, as long as it is secured and flushed. But a £20 separate safe from Argos or B&M install it same way. Important thing is that its not visible from windows or casual visitors. ...even the ££££ gun cabinets can be opened in 60sec cutting and hatch on the side with a grinder...you only need show reasonable steps to secure fac, not forth Nox. I've got a number of them and they have worked fine for years, even if made in china.