[Typo3] If column empty, show column of page X

[Bobby Eichholz]

Hello,
I've read a lot of comments in this list but didn't find a working 
solution for my problem.

I'm using a 3-column-layout, left and right columns containing small 
blocks of content. These block are all the same on most of the pages.

My idea was to create a page where I add the default content into the 
left and right column and including them per TS on every page. If a page 
needs special content in a column, it should be added to the page 
directly ignoring the default content.

I'm building the columns like this:
=====
temp.blocksLeft = CONTENT
temp.blocksLeft {
     table = tt_content
     select {
         pidInList = this
         where = colPos = 1
         orderBy = sorting
     }
     renderObj < tt_content
     renderObj {
         stdWrap.wrap = |</td></tr></table>
         image.20.maxW = 143
         image.20.maxWInText = 143
     }
     styles.content.imgtext.colSpace = 0
     styles.content.imgtext.rowSpace = 0
     styles.content.imgtext.textMargin = 0
     stdWrap.required = 1
}
=====
My idea was to replace 'stdWrap.required = 1' with 
'stdWrap.ifEmty.override.pidInList = 169' where 169 is the uid of the 
page with the default content (doesn't work, shows content of the column 
if there is or stays empty).
Next attempt was, adding:
=====
temp.blocksLeftDefault = CONTENT
temp.blocksLeftDefault {
     table = tt_content
     select {
         pidInList = 169
...
}
...
subparts.blocksLeft < temp.blocksLeft
subparts.blocksLeft.stdWrap.ifEmpty < temp.blocksLeftDefault
=====
This nearly works unless on the FE I now get the type of 
'temp.blocksLeftDefault' (CONTENT) instead of the content itself.

Thanks
Bobby