rotate figures with a pi

Hi,
I have a couple of big pictures which would fit nicely on a a4-page in landscape - orientation. To do so, I used a processing instruction as described in Mr. Stayton's book here. The problem seems that some attributes given to <figure> and <imageobject> does not have an effect to the rendered PDF. I even managed to replace the attribute to figure, pgwide="1", which seems to be ineffective because it's is going to the <fo:block> but not to the <fo:block-container>. That was easy since you just have to put the start-indent="0" attribute to this wrapper in the customization layer like that:

<xsl:template match="d:figure[processing-instruction('landscapeFigure')]">

     <fo:block-container reference-orientation="90" start-indent="0" width="100%" height="auto">
        <xsl:apply-imports/>
     </fo:block-container>
</xsl:template>

Problem is now that the scalefit="1" - attribute to the <imagedata> - element does not go through to the generated .fo so the picture is still far to big. If the fo file would look like that:

 <fo:block-container reference-orientation="90" start-indent="0" width="100%" height="auto"><fo:block start-indent="0pt">

 <fo:block space-before.minimum="0.5em" space-before.optimum="1em" space-before.maximum="2em" space-after.minimum="0.5em" space-after.optimum="1em" space-after.maximum="2em" keep-together.within-column="auto" id="d0e159">

 <fo:block space-before.optimum="1em" space-before.minimum="0.8em" space-before.maximum="1.2em" font-weight="bold" font-size="12pt" hyphenate="false" space-after.minimum="0.4em" space-after.optimum="0.6em" space-after.maximum="0.8em" font-family="inherit" keep-with-next.within-column="always">Description</fo:block>

 <fo:block id="d0e166"><fo:external-graphic src="" width="100%" height="auto" content-width="scale-to-fit" content-height="100%"/></fo:block></fo:block></fo:block></fo:block-container>

then the picture would fit on the page perfectly.
Is there a possibility to reach the scale-to-fit - instruction through or give it in the customization layer?

Any answer is appreciated.

Regards,
Benno