Horizontal shifting of a figured bass symbol

[Robert Blackstone]

Dear all,

In my experience, figured bass symbols are, or rather look, always perfectly 
aligned vertically with their bass note.
Not, however, in this case. That is, the sharp is well aligned with the left 
side of the whole note, as seen in the ME.

++++++++++++++
sh = \markup { \fontsize #-2 \sharp }
\relative c {
<<
\new Staff { \clef "bass" \time 4/2 
        
         e1 a,4. g8 f4 g |
}
\new FiguredBass {
        \figuremode { \override BassFigure #'font-size = #-2 
                < \sh >1 < _ >1 | 
}}
>>
}
+++++++++++++++

I find this rather ugly and I would like to have the sharp aligned with the 
centre of the whole note.
What can I do to shift this sharp a wee bit to the right?

Thanks in advance for all help.

Best regards,

Robert Blackstone