90 Ignition Switch

Hello there, first posting of newbie here.
Mate has ignition switch problem as title suggests. Its a 1984 A reg 90, with a Perkins 3l turbo fitted. We got switch out no bother but am unable to find one in any of the online catalogues/ stores at present, local main dealer shut (dont fancy inflated prices anyway).
Its a Lucas 157SA according to back of it, with 3 double terminals and one single for bayonet atachments. On side are numbers - 39415E & 3588. It looks like previous owner/ garage has tampered with it anyway - does this mean its difficult to replace?
Other theory I had was is it from a series model as this is an '84/ early 90?
Sorry for long winded question, any help/advice greatly appreciated, ta, Niall

You've tried Paddocks Craddocks Beamends etc etc ?

only got switch out yesterday afternoon and numbers I tried shut by then. Gonna try them all tomorrow, was just chancing my arm that someone here would know off the top of their heads

Niall,
lucas part number 35288 is the same as Land Rover part PRC2734.
Lucas part 39415 is the same as Land Rover part 579085. Both of these are the ignition switch one petrol, one diesel. PRC2734 is the one off a diesel N/A 2.5 so this may be the part you were looking for. The part number for the switch and column lock complete now superseeds to part number QRF100870.
See the piccys below to see if they look like the one you need.

Cheers loads for that, fortunately managed to find lucas parts dealer in Team Valley ( Gateshead) yesterday. Should have switch by tomorrow or saturday. Thanks very much, appreciate input loads.