Redefine lilypond 'function'

[Arno Rog]

L.S.

After every update of lilypond I have to make an adjustment to the size
of the accidentals in the figured bass 'function'.
The sharp and natural are very small and therefore hardly distinguishable;
small, especially if you compare it to the size of the figures:-(

To achieve this I adapt
.\usr\share\lilypond\current\scm\translation-functions.scm

and change row 129
   (if (not (= alt DOUBLE-SHARP))
      -2 2)

into 
   (if (not (= alt DOUBLE-SHARP))
      -0 0) <--- changed

Is there a way to redefine the function at row 103
(define-public (format-bass-figure figure event context) in my .ly file
so that I do not have to change translation-functions.scm?

Thanks in advance.

AwR