I judge the fitting to be rated at 60 W thermal; it currently has a same-sh ape LED bulb which feels to me to be about 5 W.
A replacement could be vaguely similar, or could be (OEM, & as I have) like the top of a traditional standard lamp. but the other-way up and batten-mo unting, similar to "MK Batten Lampholder Straight 1174RPWHI" on http://www. wickes.co.uk/Products/Electrical+Lighting/Electrical/MK-Logic-Plus-Switches +Sockets/MK-Ceiling-Fittings/c/1000118; or to http://www.screwfix.com/p/bri tish-general-batten-lamp-holder-white/93835.
I assume that there will not be enough cable to dangle, but that a unit lik e http://www.screwfix.com/p/british-general-6-pendant-set-white/22210 could be added.
Traditional UK BC socket preferred.
The work could be done by a reasonably skilled amateur (me), by the landlor d or his minion, or by a Proper Regs Part P (or whatever) electrician.
Suggestions / observations, preferably legal?