A couple of people suggested looking in small ad's in Sunday newspapers, Private Eye or Exchange and Mart. One or two people suggested contacting BT directly, but nobody claimed to have tries this or gave any suggestions as to which bit of BT to try. Mark Whidby (M.Whidby@mcc.ac.uk) remembers seeing a company with a yard full of 'phone boxes near Staleybridge.
(Samples from Exchange and Mart.)
One company in Essex (01277 899 495, Michael Smith) does them in off-street condition for UKP350+delivery+VAT or reconditioned at around UKP975+delivery+VAT.
Another company (0161 767 9259) does them for UKP375+delivery (off-street) or UKP1250+delivery reconditioned. They said that there was no VAT (presumably they're a smaller company who aren't VAT registered?).
They told me that customers usually found it cheaper to buy them reconditioned than to resort to DIY. Reconditioning includes stripping, filling and repainting the cast iron frame, replacing glass (including the `Telephone' signs), guilding the crowns and refurbishing the doors Customers who did their own refurbishment usually did it for pleasure or sentimental value rather than to save money.
Delivery would cost UKP125 (from their Birmingham depot to me in Essex), or I could collect if I happened to have a lorry and a fork-lift.
Suggestions for uses were showers, drinks cabinets, fish tanks, to grow plants in, to house a telephone, ...
The original K2 boxes (the ones with 6x3 almost-square panes in three of the foor walls) had teak doors. There aren't many of these left. What most people think of as a "red telephone box" is the K6 (with 8x3 very unsquare panes in three of the foor walls); they have metal doors, as do the later K8s.
Some K2s and K6s are old enough to qualify for Listed Building status. There are 216 listed K2s (213 of these in London!), and 996 listed K6s.
[Source: the excellent book "Telphone boxes" by Gavin Stamp, Chatto & Windus, 1989.]
[end of uk.telecom FAQ part 2/3]