In fact most ex-London buses are converted from dual-door into
single-door when transferred to operators in other parts of UK,
as the dual-door standard is unpopular in UK cities beside London.
The ex-Metroline Darts bought by Central Connect recently have also
been converted into single-door nicely without "remains" of the second
door at all: http://2.fpic.co.uk/p62891783.html
