Peter Beale ) gurgled happily, sounding much like they
were saying :

Former British Reg No :- BSL161, LSJ872, JSJ767

Those are all "age-related" numbers issued fairly recently

SL and SJ would have been Scottish registrations under the old system
- can't lay my hands on my 1960s Readers' Digest Book of the Road
which listed them. Could they have been some sold to Stagecoach in
Scotland, with LT hanging on to the *LT *** numbers?

They were, but they were number series that never got issued before the
annual suffix was introduced - so they've been kept (with others) for issue
to newly imported pre-63 vehicles or to pre-63 vehicles that have somehow
lost their original numbers.

http://fleetdata.co.uk/agerelated.html